Para-Rid [Discontinued] by Mountain Meadow Herbs

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Coronary heart disease (CHD). It is unclear if consuming black walnut as part of the diet can reduce the risk for CHD. Details: Epidemiological research has found that people who increase dietary consumption of nuts in general might have a lower risk of CHD and death due to coronary events. However, there is no available evidence showing that eating black walnut, specifically, reduces the risk of CHD (8478,13299). Still, in 2004, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that consuming 1.5 ounces of walnuts per day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of CHD. The FDA has concluded that this claim is based on supporting, rather than conclusive, evidence (102335).
• Wound healing. Although there is interest in using topical black walnut hull and bark for wound healing, there is insufficient reliable information about the clinical effects of black walnut for this purpose. More evidence is needed to rate the effectiveness of black walnut for these uses.

(Read more about BLACK WALNUT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Amenorrhea. Although there has been interest in using oral catnip for amenorrhea, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Anxiety. Although there has been interest in using oral catnip for anxiety, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Colic. Although there has been interest in using oral catnip for colic, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Common cold. Although there has been interest in using oral catnip for common cold, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Dyspepsia. Although there has been interest in using oral catnip for dyspepsia, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Flatulence. Although there has been interest in using oral catnip for flatulence, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Hemorrhoids. Although there has been interest in using topical catnip for hemorrhoids, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Influenza. Although there has been interest in using oral catnip for influenza, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Insomnia. Although there has been interest in using oral catnip for insomnia, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Migraine headache. Although there has been interest in using oral catnip for migraine headache, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Mosquito repellent. It is unclear if oral catnip is beneficial as mosquito repellent. Details: Preliminary clinical research shows that applying a small amount of catnip oil or certain catnip constituents to the skin is more effective at repelling yellow fever mosquitoes when compared with ethanol. However, catnip oil and catnip constituents appear to be less effective than the commercial insect repellents SS220 and DEET (40200).
• Osteoarthritis. Although there has been interest in using topical catnip for osteoarthritis, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Tension headache. Although there has been interest in using oral catnip for tension headache, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Upper respiratory tract infection (URTI). Although there has been interest in using oral catnip for URTI, there is insufficient reliable information about the clinical effects of catnip for this purpose.
• Urticaria. Although there has been interest in using oral catnip for urticaria, there is insufficient reliable information about the clinical effects of catnip for this purpose. More evidence is needed to rate catnip for these uses.

(Read more about CATNIP)

POSSIBLY EFFECTIVE

• Ventilator-associated pneumonia (VAP). Clove mouthwash might reduce the risk of acquiring pneumonia in patients on mechanical ventilation. Details: A large clinical trial in adults in the intensive care unit on mechanical ventilation shows that administration of a clove extract 6.66% mouthwash, 15 mL twice daily for 5 days, results in a 2-fold lower incidence of ventilator-associated pneumonia when compared with chlorhexidine mouthwash (112151).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Alveolar osteitis. Although there has been interest in using topical clove for alveolar osteitis, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Anal fissures. It is unclear if topical clove oil is beneficial in patients with anal fissures. Details: Preliminary clinical research in patients with chronic anal fissures shows that applying clove oil 1% cream for 6 weeks heals fissures in 60% of patients by the 3-month follow-up, compared with only 12% of patients who used topical lidocaine 5% cream and stool softeners (43487).
• Cough. Although there has been interest in using oral clove for cough, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Dental plaque. Topical clove has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that using a specific toothpaste (Sudantha, Link Natural Products Ltd.) containing a combination of clove, Acacia chundra Willd., malabar nut, bullet wood tree, black pepper, Indian beech, gall oak, Terminalia, and ginger twice daily for 12 weeks can reduce dental plaque, bleeding, and bacteria counts in the mouth when compared with placebo (43570). Other clinical research shows that administration of a mouth rinse containing clove, tea tree oil, and basil 10 mL twice daily for 21 days is as effective as a commercially available mouth rinse containing thymol, eucalyptol, menthol, and methyl salicylate in reducing dental plaque and gum inflammation (92160). It is unclear whether clove, another ingredient, or a combination of these ingredients is responsible for these effects.
• Diarrhea. Although there has been interest in using oral clove for diarrhea, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Dyspepsia. Although there has been interest in using oral clove for dyspepsia, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Flatulence. Although there has been interest in using oral clove for flatulence, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Gingivitis. Although there has been interest in using topical clove for gingivitis, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Halitosis. Although there has been interest in using oral clove for halitosis, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Hangover. It is unclear if oral clove flower extract is beneficial for reducing hangover severity. Details: Preliminary clinical research in a very small number of healthy males with a history of hangovers shows that taking a clove flower bud polyphenol extract 250 mg prior to drinking brandy (42.8% alcohol) decreases hangover severity scores by around 55% when compared with placebo (100597).
• Hyperhidrosis. It is unclear if topical clove oil is beneficial in patients with hyperhidrosis. Details: Preliminary clinical research in patients with hyperhidrosis of the palms shows that topical application of clove oil 45% in liposome base twice daily for 2 weeks improves hyperhidrosis severity and decreases the rate of sweating by around 34% when compared with a saline control (100596). The validity of these findings is limited by a lack of subject randomization.
• Impaired glucose tolerance (prediabetes). It is unclear if oral clove flower extract is beneficial in patients with prediabetes. Details: Preliminary clinical research in a very small number of patients with prediabetes shows that taking a polyphenolic extract from clove flower buds 250 mg daily for 30 days decreases pre-prandial plasma glucose by 14 mg/dL and postprandial plasma glucose by 40 mg/dL when compared to baseline (100595). The validity of these findings is limited by the very small size of the study and the lack of a control group.
• Mosquito repellent. Small clinical studies suggest that topical clove oil may repel mosquitos for up to 4-5 hours. Details: Preliminary clinical research shows that topical application of undiluted clove oil can repel 100% of mosquitoes for up to 4 hours (43427). Other preliminary research shows that topical application of gel containing clove oil 20% can repel 86% to 97% of mosquitoes for 5 hours (43411).
• Nausea and vomiting. Although there has been interest in using oral clove for nausea and vomiting, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Oral mucositis. Although there has been interest in using topical clove for oral mucositis, there is insufficient reliable information about the clinical effects of clove for this purpose.
• Pain (acute). It is unclear if topical clove is beneficial in patients with acute pain. Details: Preliminary clinical research shows that topical application of a gel containing ground cloves, applied as 4 grams of gel for 5 minutes prior to dental anesthesia injection, can reduce needle stick pain when compared with placebo. The effect of the clove gel on pain seems to be comparable to benzocaine 20% gel (43448).
• Premature ejaculation. Topical clove has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that administration of a multi-ingredient cream preparation (SS Cream) containing clove flower, Panax ginseng root, Angelica root, Cistanches deserticola, Zanthoxyl species, Torlidis seed, Asiasari root, cinnamon bark, and toad venom to the glans penis, one hour prior to intercourse and washed off immediately before intercourse, increases ejaculatory latency time by over 4-fold when compared with placebo in adults with premature ejaculation (2537). It is unclear whether clove, another ingredient, or a combination of these ingredients is responsible for these effects.
• Pruritus. There is limited evidence on the topical use of clove oil in patients with chronic pruritus. Details: Preliminary clinical research in patients with chronic pruritus shows that applying clove oil 10% in petroleum jelly to the skin twice daily for 2 weeks reduces the daily duration of itching by 48 minutes and improves symptom severity and disability scores when compared with placebo (96950). More evidence is needed to rate clove for these uses.

(Read more about CLOVE)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acne. Topical elecampane has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in young adults with facial acne shows that application of a cream containing elecampane flower and leaf 0.8%, red soapwort root 0.32%, and black nightshade leaf 0.8%, 2 to 3 times daily for 6 weeks, reduces acne severity index scores by 55%, 85%, and 91% from baseline at 2, 5, and 6 weeks, respectively, compared with no change in the placebo group (105733). The poor study methodology and lack of statistical comparison to the placebo group limit the validity of these findings.
• Cough. Oral elecampane has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children 3-6 years of age with acute cough shows that taking a specific syrup (KalobaTUSS, Schwabe Pharma Italia Srl) based on acacia honey with extracts of elecampane, mallow, great plantain, and sandy everlasting, as 5 mL four times daily for 8 days, produces rapid and sustained reductions in both nighttime and daytime cough scores when compared with placebo (105734). More evidence is needed to rate elecampane for these uses.

(Read more about ELECAMPANE)

POSSIBLY EFFECTIVE

• Dysmenorrhea. Taking fennel oil or extract by mouth may reduce pain in patients with primary dysmenorrhea. This benefit may be similar to ibuprofen or mefenamic acid. Details: Two separate meta-analyses in patients with primary dysmenorrhea show that taking fennel oil or fennel extract for 1-6 menstrual cycles reduces dysmenorrhea pain when compared with placebo. Improvement in pain was similar when compared with ibuprofen or mefenamic acid. In the included studies, doses of fennel oil ranged from 3-30 drops every 4-8 hours, and doses of fennel extract ranged from 30-230 mg daily (104196,108972). However, most studies included in these meta-analyses were small and low-quality, and all studies were conducted in Iran. Higher quality studies in other geographic locations are needed to confirm these findings.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Anxiety. Although there has been interest in using oral fennel for anxiety, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Bronchitis. Although there has been interest in using oral fennel for bronchitis, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Cancer. Although there has been interest in using oral fennel for cancer prevention, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Cholera. Although there has been interest in using oral fennel for cholera, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Colic. Small clinical studies suggest that oral fennel may reduce crying time in infants with colic. However, most research to date has evaluated fennel in combination with other ingredients. Details: A meta-analysis of three small clinical studies shows that giving fennel to infants with colic can reduce crying time by about 72 minutes daily when compared with placebo (97497). However, the studies included in this meta-analysis were at medium to high risk of bias, and the placebo response rate was high in all of the included studies. Additionally, two of the three studies evaluated combination products (16735,19715,49428). In the one study that used fennel alone, administering 5-20 mL of fennel seed oil 0.1% emulsion daily for one week led to colic relief in 65% of infants, compared with 24% of infants receiving placebo (49428). The other studies evaluated fennel in combination with lemon balm and German chamomile (ColiMil) or in combination with chamomile, vervain, licorice, and lemon balm (Calma-Bebi, Bonomelli). These combination products produced a response in 57% to 85% of infants, compared with 26% to 49% of infants receiving placebo (16735,19715).
• Constipation. Oral fennel has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small crossover trial in patients with constipation shows that drinking an herbal tea containing 3 grams of a combination of fennel, anise, elderberry, and senna daily for 5 days can decrease colonic transit time, increase the number of daily evacuations, and improve the perception of bowel function when compared with placebo (49494). Another small clinical study in elderly patients with constipation shows that drinking a specific tea (Smooth Move, Traditional Medicinals) containing fennel, senna, licorice, orange peel, cassia cinnamon, coriander, and ginger for 28 days can increase the number of bowel movements when compared to baseline (46196). The validity of this finding is limited by the lack of a comparator group. Additionally, a small clinical study in patients aged 60-65 years with functional constipation shows that taking a traditional Iranian combination product containing 5 grams each of fennel seed and rose flower, dissolved in water twice daily before meals for 4 weeks, improves constipation severity and stool consistency when compared with polyethylene glycol 10 grams. Improvements in constipation severity persisted in both groups 4 weeks after treatment completion (108973). However, polyethylene glycol is usually taken at a higher dose of 17 grams daily, limiting the validity of these findings.
• Cough. Although there has been interest in using oral fennel for cough, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Dementia. Although there has been interest in using oral fennel for dementia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Diabetes. Although there has been interest in using oral fennel for diabetes, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Dyspepsia. Although there has been interest in using oral fennel for dyspepsia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Flatulence. Although there has been interest in using oral fennel for flatulence, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Hirsutism. It is unclear if topical fennel is beneficial in patients with hirsutism. Details: A small clinical study in females with male pattern body hair due to unknown causes shows that applying a fennel 2% cream twice daily for 12 weeks can reduce hair diameter by approximately 19% when compared with placebo (49429).
• Insomnia. Although there has been interest in using oral fennel for insomnia, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Irritable bowel syndrome (IBS). Oral fennel has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in adults with either diarrhea- or constipation-predominant IBS shows that taking two capsules containing fennel essential oil 25 mg and curcumin 42 mg per capsule (CU-FEO, Alfa Wassermann S.p.A.) twice daily for 30 days improves overall ratings of abdominal pain, abdominal distention, and quality of life by 24% when compared with placebo (97422).
• Lactation. Although there has been interest in using oral fennel to stimulate breastmilk production, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Menopausal symptoms. Small clinical studies suggest that oral fennel oil or fennel seed powder may modestly improve menopausal symptoms. Details: One small clinical trial in adults with medium severity menopausal symptoms shows that taking fennel essential oil 60 mg daily for 8 weeks improves scores on the Menopause Rating Scale when compared with a sunflower oil placebo (97498). Another small clinical study in postmenopausal adults shows that taking fennel seed powder 2 grams daily for 8 weeks improves scores on the Kupperman Menopausal Index when compared with placebo (104198). Fennel has also been evaluated in combination with other ingredients. One small clinical study shows that taking a combination of fennel 120 mg, chamomile 1000 mg, and saffron 60 mg daily for 12 weeks reduces physical, psychological, and urogenital symptom scores on the Menopause Rating Scale when compared with placebo or lower doses of the combination (103628). Additionally, a moderate-sized clinical study in postmenopausal women conducted in Iran shows that taking combined fennel and valerian extract 500 mg twice daily for 8 weeks modestly improves self-reported scores for frequency and severity of hot flashes but does not improve sleep quality or duration of hot flashes when compared with placebo (112369). However, it is unclear if these benefits are due to fennel, other ingredients, or the combination.
• Nausea and vomiting. Although there has been interest in using oral fennel for nausea and vomiting, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Nocturnal enuresis. Although there has been interest in using oral fennel for nocturnal enuresis, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Osteoarthritis. It is unclear if oral fennel extract is beneficial in patients with knee osteoarthritis. Details: A small clinical trial in females with osteoarthritis of the knee shows that taking powdered fennel extract 800 mg daily for 2 weeks reduces pain and disability scores, but not stiffness, when compared with placebo (104199).
• Polycystic ovary syndrome (PCOS). It is unclear if oral fennel is beneficial in patients with PCOS. Details: A small clinical study in patients with PCOS shows that taking two fennel capsules, containing anethole 21-27 mg per capsule, daily along with a hypocaloric standard diet or a hypocaloric high-protein diet for 3 months does not reduce body weight or improve androgenic parameters such as testosterone levels, sex hormone-binding globulin levels, or free androgen index, when compared with these diets plus placebo (104197). Fennel has also been evaluated in combination with other ingredients. A clinical study in patients with oligomenorrhea due to PCOS shows that taking a traditional combination product (Aslagh) containing equivalent amounts of essential oils of fennel, wild carrot seeds, and Vitex agnus-castus fruit for 3 months, either alone or in combination with metformin, improves rates of menstrual bleeding and menstrual cyclicity similarly to metformin alone. All three groups experienced a significant improvement from baseline. Aslagh was taken as two, 500-mg capsules twice daily, except during menses; metformin was titrated over one week to a dose of 500 mg three times daily (108974). Additionally, a moderate-sized clinical study in patients with PCOS shows that taking fennel 60 mg and Elwendia persica 25 mg twice daily for 4 months modestly improves number of ovarian follicles and body mass index when compared with placebo; however, when compared to baseline, the combination also improves hirsutism scores and menstrual cycle duration and interval (112370). It is unclear if these effects are due to fennel, other ingredients, or the combination.
• Rheumatoid arthritis (RA). Although there has been interest in using oral fennel for RA, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Sexual desire. It is unclear if oral fennel is beneficial for improving sexual desire. Details: A small clinical study in postmenopausal adults shows that taking fennel seed powder 2 grams daily for 8 weeks does not improve scores on the Hurlbert Index of Sexual Desire when compared with placebo (104198).
• Sunburn. It is unclear if topical fennel emulsion is beneficial for preventing sunburn. Details: A small clinical study shows that applying a fennel 5% emulsion topically prior to ultraviolet (UV) exposure can reduce sunburn by 65% when compared with a control (49518).
• Upper respiratory tract infection (URTI). Although there has been interest in using oral fennel for upper respiratory tract infections, there is insufficient reliable information about the clinical effects of fennel for this purpose.
• Vaginal atrophy. It is unclear if intravaginal application of fennel cream is beneficial in patients with vaginal atrophy. Details: A small clinical study in postmenopausal adults shows that applying 5 grams of a fennel 5% cream to the vagina once daily for 8 weeks seems to reverse vaginal thinning, improve vaginal pH, and reduce symptoms of vaginal atrophy such as itching, dryness, and pain with intercourse when compared with placebo (92509). Patients in the fennel group also rated their sexual function to be improved when compared with those receiving placebo (97496). More evidence is needed to rate fennel for these uses.

(Read more about FENNEL)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Cancer. Although there has been interest in using topical gentian for cancer, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Diabetes. Although there has been interest in using oral gentian for diabetes, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Diarrhea. Although there has been interest in using oral gentian for diarrhea, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Flatulence. Although there has been interest in using oral gentian for flatulence, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Gastritis. Although there has been interest in using oral gentian for gastritis, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Gastroesophageal reflux disease (GERD). Although there has been interest in using oral GERD for diarrhea, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Hypertension. Although there has been interest in using oral gentian for hypertension, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Malaria. Although there has been interest in using oral gentian for malaria, there is insufficient reliable information about the clinical effects of gentian for this purpose.
• Obesity. It is unclear if oral gentian is beneficial for obesity. Details: Preliminary clinical research in healthy adults shows that consuming a pudding containing microencapsulated gentian root extract 1.25 g at breakfast modestly reduces caloric intake over 24 hours, but does not affect self-reported feelings of hunger or fullness, when compared with placebo pudding (96534).
• Rhinosinusitis. Oral gentian has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a specific combination product (SinuComp; Sinupret) that contains gentian root 6 mg , elderflower, verbena, cowslip flower, and sorrel improves the symptoms of acute or chronic sinusitis when compared with placebo (374,379). Observational research in adults with acute rhinosinusitis suggests that taking the same combination product orally three times daily, in addition to topical mometasone furoate nasal spray, for 7 days is associated with lower symptom scores when compared with mometasone nasal spray alone (95907).
• Wound healing. Although there has been interest in using topical gentian for wound healing, there is insufficient reliable information about the clinical effects of gentian for this purpose. More evidence is needed to rate gentian for these uses.

(Read more about GENTIAN)

POSSIBLY EFFECTIVE

• Dysmenorrhea. In people with dysmenorrhea, taking oral ginger seems to reduce pain. Clinical research shows that ginger might be comparable to ibuprofen or mefenamic acid. In addition, taking ginger seems to be beneficial when used as an adjunct to mefenamic acid 250 mg twice daily. Details: Clinical research in individuals at least 15 years of age shows that ginger can reduce pain from dysmenorrhea. Clinical studies show that taking ginger powder 500-2000 mg daily usually for the first 3-4 days of a menstrual cycle modestly decreases pain severity by an average of 2.3-2.7 points on a 10-point scale when compared to control groups (89889,89899,91139,91892,96255,106077). However, a meta-analysis of clinical research shows that taking ginger does not reduce pain duration when compared with placebo (106077). Clinical research also shows that ginger might be as effective as some anti-inflammatory agents. Taking a specific ginger extract (Zintoma, Goldaru) 250 mg four times daily for 3 days at the beginning of the menstrual period or until pain relief improves symptoms similarly to ibuprofen or mefenamic acid (17931,96259,106077). Also, taking a ginger extract 200 mg four times daily for 3-4 days at the beginning of pain is equally effective to taking Novafen, a combination of acetaminophen, caffeine, and ibuprofen (99444). Ginger also seems to improve pain when given as an adjunct to anti-inflammatory agents. A small clinical study in young females with dysmenorrhea shows that adding ginger (Vomigone, Dineh Co.) 500 mg daily to mefenamic acid 250 mg twice daily for 5 days further reduces pain when compared with taking mefenamic acid alone (102464).
• Osteoarthritis. Most clinical research shows that taking ginger extract by mouth improves pain in some patients with osteoarthritis. Topical ginger, on the other hand, has not shown benefit for knee osteoarthritis in low quality research. Details: Meta-analyses of clinical research show that taking ginger extract 500-1000 mg daily for 3-12 weeks can modestly improve pain when compared with placebo in some patients with osteoarthritis of the knee or hip (96253,103357). However, a meta-analysis of two clinical studies shows that taking ginger extract about 500 mg daily for 6 weeks does not have an effect on function (103357). Some clinical research has also compared ginger to conventional drug treatment. In one clinical trial, there was no significant difference between ginger extract 30 mg daily and ibuprofen 400 mg three times daily for one month in patients with osteoarthritis of the hip or knee (17930). However, taking a specific ginger extract (Eurovita Extract 33; EV ext-33) orally 170 mg three times daily for 3 weeks was significantly less effective than ibuprofen 400 mg three times daily for reducing pain (7048). Since ginger is thought to take several weeks for significant benefit, this trial might not have lasted long enough. Ginger has also been compared with diclofenac. When used orally as 1500 mg daily in two divided doses, ginger is less effective than oral diclofenac 100 mg daily in two divided doses, or the combination of ginger and diclofenac, for 12 weeks (89898). Various studies have evaluated formulations containing ginger with other ingredients. These combinations have all been shown to improve osteoarthritis pain, and in some cases, functionality. Studied formulations include ginger (Eurovita Extract 35; EV ext-35) 340 mg with glucosamine (Zinaxin glucosamine, Ferrosan AS) 1000 mg daily for 4 weeks, a ginger extract with an alpinia (Alpinia galanga) extract (Eurovita Extract 77; EV ext-77) 255 mg twice daily for 6 weeks, a ginger extract with curcuminoids, and extracts of devil's claw, Boswellia serrata, and celery (Tregocel) for 36 weeks, or Ayurvedic shunthi-guduchi formulations containing ginger, Indian gooseberry, and Tinospora cordifolia, either with or without Boswellia serrata (7084,18210,89557,106078). However, it's too early to know if the effects of these combination agents are associated with ginger or other ingredients in the formulations. Topical ginger, alone or in combination with other ingredients, has also been studied for knee osteoarthritis. Although a meta-analysis of two randomized clinical trials shows no evidence of benefit of topical ginger for pain and disability when compared with placebo or standard therapy (103357), some benefits have been shown in individual preliminary studies (20340,20341,89897,96668,97537,97542). These trials have used a specific gel containing ginger and plai 4% by weight (Plygersic gel, Thailand Institute of Scientific and Technological Research) 4 grams/day in four divided doses for 6 weeks (89897), an ointment composed of ginger, cinnamon, mastic (Saghez), and sesame oil twice daily for 6 weeks (20340), or one gram of ginger extract 5% (standardized to 11.18% of 6-gingerol) in a nanostructure lipid carrier three times daily for up to 12 weeks to the affected knee (96668,97537). Some studies have used ginger essential oil in a massage oil, alone or with sweet orange essential oil or standard therapy, twice weekly for 3 or 6 weeks (20341,97542).
• Pregnancy-induced nausea and vomiting. Oral ginger seems to reduce the severity of nausea and vomiting in some people during pregnancy. Ginger seems to be more effective than placebo, comparable to vitamin B6 or dimenhydrinate, and less effective than metoclopramide. Details: Although most clinical studies are small and have methodological limitations, the available research shows that ginger is more effective than placebo, and comparable to vitamin B6 or dimenhydrinate (721,1922,5343,11346,13071,16306,20312,20315,90103,91201,102462). Although ginger is comparable to dimenhydrinate for reducing symptoms of morning sickness, it seems to take about 3 days to reduce vomiting episodes compared to 1 day with dimenhydrinate (16305). In addition, clinical research shows that ginger is less effective than metoclopramide at relieving nausea and vomiting associated with pregnancy (20315). Ginger doses of 500 to 2500 mg daily, divided into two to four daily doses for 3 days to 3 weeks, have been used in clinical research (721,5343,16305,16306,20312,20315,90103,91201). The American College of Obstetrics and Gynecology (ACOG) considers ginger capsules 250 mg 4 times daily a first-line nonpharmacological treatment option for pregnancy-induced nausea based on limited evidence. However, there is no evidence that ginger reduces vomiting (111601).

POSSIBLY INEFFECTIVE

• Chemotherapy-induced nausea and vomiting (CINV). Most clinical research shows that oral ginger does not reduce acute or delayed CINV. The effect of ginger might depend on the dose, the other antiemetics used, or the specific chemotherapy regimen. Details: Most clinical research shows that taking ginger as adjunct to adequate antiemetic therapy does not reduce DELAYED CINV when compared with antiemetic therapy alone (20316,96260,89891,96675,97538,97541,101760,102461,113616). Clinical research from meta-analyses and most individual clinical studies also show that taking ginger 0.5-3.5 grams as an adjunct to standard antiemetic therapy does not reduce the incidence or severity of ACUTE CINV when compared with antiemetic therapy alone (89891,96675,101760,102461,102466,113616). However, conflicting results exist from some individual clinical studies (20316,102466). These individual studies evaluated powdered ginger root or liquid extract of ginger root 0.5-2 grams taken in two to four divided doses daily, starting on either the day of or 3 days before chemotherapy and continuing for 3-5 days after chemotherapy initiation (20316,102466). Also, one small study shows that ginger in doses of 1 gram or less for more than 3 days reduces the likelihood of acute vomiting by 60% (101760). More research is needed to confirm the efficacy of this lower dose. Reasons for the conflicting results are unclear, but several theories have been postulated. One theory is that ginger might help reduce CINV associated with some, but not all, chemotherapy regimens. One preliminary clinical study shows that ginger 500 mg twice daily for 3 days reduces vomiting in patients receiving cyclophosphamide and doxorubicin, but not in patients also receiving 5-fluorouracil or docetaxel (96251). However, since there is limited evidence supporting this theory, additional research is needed to confirm. Another theory is that ginger helps when used with certain antiemetic drugs, but not others. For example, ginger seems to help in cases when optimal antiemetic therapy, such as 5-HT3 receptor antagonists, is not available. Small clinical studies show that ginger reduces the severity of acute nausea when compared with prochlorperazine or metoclopramide, both of which are suboptimal antiemetic therapy for CINV (89891). Another small study shows that ginger is comparable to metoclopramide for improving delayed chemotherapy-induced nausea (13244). On the other hand, several studies show that taking ginger 0.5-2 grams daily along with antiemetic therapy that includes aprepitant does NOT improve acute or delayed CINV (20318,89891,96251,96675). In fact, one study found an association between concomitant use of ginger 2 grams daily with aprepitant and worsened severity of delayed nausea. Ginger is hypothesized to decrease the absorption of aprepitant and reduce its effectiveness for delayed nausea (20318,96675). However, this effect has not been replicated, and aprepitant serum levels were not measured to confirm this hypothesis. Finally, many of the studies showing a benefit of ginger for CINV when used as an adjunct to standard antiemetic therapy are considered to be methodologically flawed (20317,96252,96677). For instance, one study using powdered ginger root 1-2 grams daily during the first three days of chemotherapy in children and adults (20317) has been criticized for inaccurately representing data (89891). Other studies of ginger 500 mg twice daily for up to 10 days used questionable methods to measure outcomes and usually did not differentiate between acute and delayed CINV (96252,96677). Ginger essential oil aromatherapy has also been evaluated. One small study shows that using two drops of ginger essential oil on an aromatherapy necklace for 2 minutes daily for 5 days, starting on the first day of chemotherapy, reduces acute nausea, but not vomiting or delayed nausea, when compared with placebo in females with breast cancer taking standard antiemetics including granisetron, dexamethasone, and metoclopramide (96256).
• Exercise-induced muscle soreness. Most research shows that oral ginger in single or multiple doses does not prevent or treat exercise-induced muscle soreness. Details: Two small studies in healthy adults show that single doses of ginger supplements do not seem to reduce muscle soreness from exercise. Taking capsules of ground ginger 2 grams, 30 minutes before a 30-minute cycling bout, or 24-48 hours after eccentric exercise, does not reduce muscle pain during exercise or within one hour of ingestion when compared with placebo (17932,17934). Taking multiple doses also does not seem to help. One small study in healthy adults shows that taking capsules with ginger powder 4 grams daily for 5 days before high-intensity eccentric exercise does not reduce muscle soreness over 4 days when compared with placebo (96258). Another small study in healthy adults shows that taking capsules of heated or raw ground ginger 2 grams daily for 8 days prior to eccentric exercise, and continuing supplementation for 3 more days, might modestly reduce muscle soreness 24 hours post-exercise, but not at later time points, when compared with placebo (17933,96258). Ginger has also been tested in combination with other ingredients. One small study in healthy adults shows that taking a specific combination product (ReWin(d), Natural Origins) containing a 4:3 ratio of ginger and annatto powder, 2 grams in divided doses daily for 4 weeks before eccentric exercise and continuing for 3 days after exercise, may modestly reduce muscle pain 48 hours after exercise but not at other time points (105057). This study was funded by the supplement manufacturer.
• Motion sickness. Most research shows that oral ginger does not prevent or treat motion sickness. Details: Most clinical research shows that taking ginger 500-1000 mg up to 4 hours prior to travel does not prevent motion sickness (7624,7625,20330,20331). Some patients report subjective feelings of improvement, but in many studies objective measures did not significantly improve (7400). However, one clinical trial suggests that ginger is more effective than dimenhydrinate at reducing gastrointestinal distress associated with motion sickness (20332). Another clinical study seems to show that taking ginger 1-2 grams as a single dose reduces nausea severity and increases the latency before the onset of nausea caused by simulated motion sickness when compared to baseline (20333). The validity of this finding is limited by the lack of a comparator group.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Acute respiratory distress syndrome (ARDS). Some small clinical studies show that giving ginger with tube feeds to hospitalized patients might reduce the duration of serious sequelae from ARDS. Details: A small clinical trial in adults with ARDS shows that administering ginger extract 120 mg in three divided doses daily via nasogastric tubing for 21 days increases the number of ventilator-free days and the amount of feeding tolerated and decreases the number of intensive care unit (ICU) days when compared with placebo. However, it does not seem to improve overall mortality (20343). Also, another small clinical study shows that adding ginger extract 120 mg to tube feeds in three divided doses daily for 8-21 days improves blood oxygen levels by 13% to 20%, as well as the ability of the lungs to expand by 17%, when compared with a coconut oil placebo. The duration of mechanical ventilation and stay in the ICU also improved. However, ginger does not affect other measurements of lung function or physical organ damage in these patients (89886).
• Allergic rhinitis (hay fever). It is unclear if oral ginger is beneficial in allergic rhinitis. Details: A small clinical trial shows that taking ginger extract 500 mg daily for 6 weeks is as effective as loratadine 10 mg daily for reducing nasal symptoms of allergic rhinitis (103359).
• Antiretroviral-induced nausea and vomiting. Oral ginger seems to improve nausea and vomiting in patients using antiretroviral agents. Details: A small clinical study in patients with HIV shows that taking ginger 0.5 grams twice daily, 30 minutes prior to each dose of antiretroviral for 14 days, reduces the relative likelihood of nausea and vomiting by about 63% and 79%, respectively, when compared with placebo (89887).
• Asthma. Although there has been interest in using oral ginger for asthma, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Back pain. Although there has been interest in using oral ginger for back pain, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Burns. Although there has been interest in using topical ginger for burns, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Cancer-related anorexia. It is unclear if oral ginger improves appetite in people with cancer-related anorexia. Details: A small clinical study in patients with cancer-related anorexia and cachexia shows that taking a capsule containing ginger 1650 mg daily for 14 days improves nausea, appetite, reflux, dysmotility, and other gastrointestinal symptoms when compared to baseline (102460). The validity of these findings is limited by the lack of comparator group.
• Chronic obstructive pulmonary disease (COPD). Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking two capsules of a specific combination product (AKL1, AKL International Ltd.) containing ginkgo extract, ginger, and Picrorhiza kurroa twice daily for 8 weeks does not improve respiratory symptoms when compared with placebo in patients with COPD (89702). Another moderate-sized clinical study in adults with COPD shows that taking a combination product containing extracts of ginger, alpinia, cardamom, cinnamon, and saffron in honey 3 times daily for 8 weeks improves confidence in leaving home and the ratio of forced exploratory volume per second to forced vital capacity of the lungs (FEV1/FVC) when compared with placebo. However, the combination product does not improve most measures of respiratory function or symptoms such as cough, phlegm, chest tightness, dyspnea, reduced energy levels, sleeping disorders, or activity limitations when compared with placebo (111542). It is unclear if these effects are due to ginger, other ingredients, or the combination.
• Colic. Although there has been interest in using oral ginger for colic, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Constipation. Although there has been interest in using oral ginger for constipation, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Coronavirus disease 2019 (COVID-19). It is unclear whether oral ginger is beneficial for patients with COVID-19. Details: Clinical research in adults hospitalized with asymptomatic COVID-19 infection shows that taking ginger 1.5 grams twice daily orally until hospital discharge reduces length of stay from around 8.5 days to 6 days, when compared with placebo. The strongest effect is seen in males over 60 years of age (110005). The relevance of these results is reduced by a lack of blinding, and the fact that the subjects were initially asymptomatic. The efficacy of ginger for treating COVID-19 has also been evaluated in combination with other ingredients. In adults with uncomplicated, moderate COVID-19, taking a combination of ginger, turmeric, ashwagandha, and boswellia (BV-4051, Artovid-20), 1776 mg twice daily orally for 14 days in addition to standard care and starting 48-96 hours after symptom onset, reduces the mean duration of symptoms from about 8 days to 7 days, when compared with placebo (109899). A small open-label study in adults with confirmed mild to moderate COVID-19 shows that taking ginger 1000 mg and ashwagandha 500 mg twice daily for 15 days, along with conventional therapy, leads to a 13.8-fold and 2.6-fold increase in the relative rate of clinical cure at 7 days and 15 days, respectively, when compared with conventional therapy alone. Taking this combination also appears to reduce time to recovery by around 6 days but does not improve the rate of negative COVID-19 tests, chest imaging findings, viral clearance, serum antibodies, or other measures of disease progression when compared with conventional therapy alone (112094). The validity of these findings is limited by a lack of blinding, and the study may have been inadequately powered to detect a difference between groups. Additionally, it is unclear if these effects are due to ginger, ashwagandha, or the combination.
• Diabetes. Some preliminary clinical studies suggest that oral ginger might have a small beneficial effect on glycemic control in patients with type 2 diabetes or gestational diabetes. Details: Meta-analyses of several small clinical trials in adults with type 2 diabetes show that taking ginger 1200-3000 mg daily for 8-13 weeks reduces glycated hemoglobin (HbA1c) by around 0.6% to 1% and fasting blood glucose by 19-21 mg/dL when compared with placebo (96680,107898). Additionally, a small clinical study in adults with diabetes on hemodialysis for end stage renal disease shows that taking ginger powder 2000 mg daily for 8 weeks reduces fasting blood glucose and measures of insulin resistance, but not serum insulin levels, when compared with placebo (111543). In patients with gestational diabetes at weeks 24-28 of pregnancy, clinical research shows that taking ginger 1500 mg daily in three divided doses for 6 weeks reduces fasting blood glucose, insulin levels, and measures of insulin resistance by a small amount when compared with placebo, with no effect on postprandial glucose levels (103358).
• Diarrhea. Although there has been interest in using oral ginger for various types of diarrhea, including cholera and acute bacterial dysentery, there is insufficient reliable information about the clinical effects of ginger for these conditions.
• Dry mouth. It is unclear if rinsing the mouth with ginger extract is beneficial for dry mouth. Details: In patients with dry mouth related to type 2 diabetes, clinical research shows that use of a ginger extract 25% mouthwash 20 mL three times daily for 14 days modestly reduces symptoms of dry mouth when compared with rinsing with a saline control mouthwash (106068). Although this study was indicated as being triple-blind, it is unclear how the taste of ginger was masked.
• Dyspepsia. It is unclear if oral ginger is beneficial for dyspepsia. Details: In patients with dyspepsia, a small clinical trial shows that a single dose of ginger root powder 1.2 grams, taken 1 hour prior to eating, does not reduce abdominal discomfort when compared with placebo. However, it increases the rate of gastric emptying (20325).
• Erectile dysfunction (ED). It is unclear if oral ginger is beneficial for erectile dysfunction. Details: Preliminary clinical research in middle-aged males with ED shows that taking two capsules of a specific combination product (Revactin, MD Concepts LLC) containing ginger root 250 mg, muira puama 250 mg, guarana 250 mg, and L-citrulline 800 mg twice daily for 3 months improves scores related to erectile function and intercourse satisfaction, but does not improve sexual desire or orgasmic function scores, when compared to baseline (103224). This study is limited by the lack of a placebo control, the use of per-protocol analysis, and a high dropout rate. In fact, 44% of patients withdrew in order to resume use of phosphodiesterase type 5 (PDE5) inhibitors. Further, it is unclear if these effects are due to ginger, other ingredients, or the combination.
• Gastroenteritis-associated nausea and vomiting. It is unclear if oral ginger is beneficial for children with gastroenteritis-associated vomiting. Details: In children aged 1-10 years with acute gastroenteritis-associated vomiting, clinical research shows that taking a single dose of ginger reduces the risk of vomiting at least once in the subsequent 8 hours by 20% when compared with placebo. The incidence of vomiting over the next 24 and 48 hours was also modestly reduced. The children were given 20 drops of ginger equivalent to 10 mg immediately, followed by every 8 hours until cessation of vomiting. All children were offered hypotonic oral rehydration solution (ORS) 30 minutes after the first dose (106076). The number of children accepting ORS, and the quantity of ORS consumed, was less in the group receiving placebo. It is unclear if this affected the outcomes of this study. Also, the incidence or severity of nausea was not investigated.
• Hangover. It is unclear if oral ginger is beneficial for managing symptoms of hangover. Details: Preliminary clinical research shows that use of a decoction containing a combination of ginger 6 grams, pith of Citrus tangerine 3 grams, and brown sugar decreases symptoms of alcohol hangovers, including nausea, vomiting, and diarrhea, when compared with placebo. The decoction was taken once 5 hours prior to drinking alcohol or four times after drinking alcohol (20320).
• Hyperlipidemia. Oral ginger may be modestly beneficial for some patients with hyperlipidemia. Details: A meta-analysis of preliminary clinical research in adults with and without hyperlipidemia shows that taking ginger 200-3000 mg orally daily for 2-24 weeks reduces triglyceride and low-density lipoprotein cholesterol levels by 12 mg/dL and 5 mg/dL, respectively, and increases high-density lipoprotein cholesterol levels by 1 mg/dL when compared with placebo (109521). However, the validity of this study is limited by high heterogeneity. A clinical study in adults with hyperlipidemia shows that taking ginger powder 1 gram three times daily for 45 days reduces triglyceride and cholesterol levels by an additional 36% and 90%, respectively, when compared with placebo (20327).
• Hypertension. It is unclear if oral ginger is beneficial for lowering blood pressure. Details: A preliminary clinical study in patients with diabetes and elevated systolic blood pressure shows that drinking black tea containing ginger 3 grams three times daily for 8 weeks does not reduce blood pressure by a clinically significant amount when compared with plain black tea (96669).
• Hypothyroidism. It is unclear if oral ginger is beneficial in patients with hypothyroidism. Details: A small clinical study in patients with primary hypothyroidism who are stabilized on thyroid hormone therapy shows that taking ginger powder 500 mg twice daily for 30 days improves symptoms associated with hypothyroidism, including cold intolerance, constipation, dizziness, dry skin, weight gain, and concentration and memory issues, when compared with placebo. However, ginger supplementation does not seem to improve hair loss, hearing, nail fragility, speech, or feelings of depression in these patients (107903).
• Insect bite. It is unclear if topical ginger is beneficial for reducing the size of insect bites. Details: Preliminary clinical research shows that a topical application of Trikatu, which contains ginger, long pepper, and black pepper extracts with 0.074% piperine and 0.046% gingerol, does not reduce the papule size associated with mosquito bites when compared with a control compound containing the same base ingredients of camphor 2%, menthol 2%, and eucalyptus oil 4% (89893).
• Intraoperative nausea and vomiting (IONV). It is unclear if oral ginger is beneficial for preventing IONV. Details: Clinical research in individuals undergoing elective C-section and receiving cimetidine and metoclopramide, shows that taking ginger 1 gram orally 30 minutes prior to anesthesia reduces the number of episodes of intraoperative nausea, but not vomiting, when compared with placebo (89890). In other clinical research in adults undergoing elective surgical procedures, adding ginger to a high calorie drink consumed pre-operatively reduces the incidence of nausea from 40% to 10%, and the incidence of vomiting from 25% to 10% when compared with the high calorie drink alone (110007). The validity of these results is unclear as only patients were blinded to the treatment group.
• Irritable bowel syndrome (IBS). Oral ginger might reduce symptoms of IBS when used in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial shows that taking ginger 1-2 grams daily for 28 days does not improve symptoms or the number of responders when compared with placebo (90102). However, some research shows that ginger might be beneficial in some patients when used along with other herbal ingredients. Taking a capsule containing ginger, boswellia, and yarrow three times daily for 30 days reduces the frequency and severity of abdominal pain, as well as the severity of bloating, when compared with placebo in females, but not males, with mild to moderate IBS (96673). Another clinical study shows that taking an herbal mixture containing ginger, English horsemint, and purple nut sedge tuber three times daily for 8 weeks improves IBS symptoms including abdominal pain, stool frequency, stool consistency, incomplete evacuation, and urgency, when compared to baseline; these improvements are similar to those achieved by taking mebeverine 135 mg three times daily (89900). However, it is unclear if these effects are due to ginger, other ingredients, or the combination.
• Joint pain. Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research shows that taking a specific combination product (Instaflex Joint Support, Direct Digital) containing glucosamine sulfate 1500 mg, methylsufonlylmethane 500 mg, white willow bark extract 250 mg, ginger root concentrate 50 mg, Boswellia extract 125 mg, turmeric root extract 50 mg, cayenne 40 m H.U. 50 mg, and hyaluronic acid 4 mg in three divided doses daily for 8 weeks reduces joint pain severity by 37% compared to only 16% with placebo. However, it does not improve joint stiffness or function when compared with placebo (89560). It is unclear if these effects are due to ginger, other ingredients, or the combination.
• Menorrhagia. It is unclear if oral ginger is beneficial for menorrhagia. Details: Preliminary clinical research in healthy adults experiencing heavy menstrual bleeding shows that taking ginger 250 mg three times daily for 4 days, starting the day prior to menstruation, and repeating for three menstrual cycles, reduces the amount of menstrual bleeding when compared with placebo (96672).
• Menopausal symptoms. Although there has been interest in using oral ginger for menopausal symptoms such as insomnia, there is insufficient reliable information about the clinical effects of ginger for this purpose.
• Migraine headache. Small clinical studies suggest that oral ginger may modestly reduce migraine pain severity and duration. However, taking ginger doesn't seem to PREVENT migraines. Details: Ginger does not seem to be effective for the prevention of migraines. Clinical research in patients with episodic migraine shows that taking ginger extract 200 mg three times daily for 3 months does not reduce the number of migraine attacks, the use of analgesics, or the number of days with pain, any more than taking placebo (101761). However, ginger may be beneficial for the treatment of migraine. Clinical research shows that taking ginger extract 400 mg orally in the emergency room along with intravenous ketoprofen 100 mg reduces pain over the next 2 hours when compared with ketoprofen and placebo. This combination also resulted in an overall better response with a higher likelihood of having no or mild pain with treatment (101762). Taking ginger 250 mg at the onset of a common migraine headache seems to be as effective as taking sumatriptan 50 mg for reducing headache severity within two hours of treatment (89894). Furthermore, a combination of ginger and feverfew (GelStat Migraine, GelStat Corporation; LipiGesic M, PuraMed BioScience), administered sublingually at the onset of a migraine attack, decreases the duration and intensity of migraine pain when compared with placebo (19357,22602). It is unclear if these effects are due to ginger, feverfew, or the combination. Feverfew alone has demonstrated some benefit in treating migraines.
• Multiple sclerosis (MS). It is unclear if oral ginger is beneficial for MS. Details: A small clinical study in adults with MS shows that taking ginger 500 mg three times daily for 12 weeks reduces disability scores and improves physical and psychological quality of life scores when compared with placebo (111541). Another small clinical study in adults with relapsing-remitting MS shows that taking ginger 500 mg three times daily for 12 weeks reduces the frequency and severity of nausea and constipation and the severity but not frequency of bloating when compared with placebo. However, no improvement was noted in other gastrointestinal symptoms of MS including abdominal pain, anorexia, diarrhea, dysphagia, gas, or heartburn (113614).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral ginger is beneficial for NAFLD. Details: A small clinical study in patients with NAFLD shows that taking ginger 1000 mg twice daily for 12 weeks improves liver steatosis scores but not liver fibrosis scores when compared with placebo. Ginger also modestly improves levels of alanine aminotransferase and gamma-glutamyl transferase but not aspartate aminotransferase (113615). However, it is unclear whether any improvements are clinically significant. Another small clinical study in patients with NAFLD shows that taking ginger root 1500 mg daily for 12 weeks reduces low-density lipoprotein (LDL) cholesterol and fasting blood glucose levels, but does not affect triglycerides, high-density lipoprotein (HDL) cholesterol, insulin resistance, blood pressure, or fatty liver index, when compared with placebo (102465).
• Obesity. Oral ginger has primarily been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Although some individual research disagrees (40802), a meta-analysis and most individual clinical trials show that taking ginger alone or with other ingredients does not reduce weight by a clinically significant amount when compared with placebo in overweight or obese individuals (20346,20347,96676,109521). Ginger has been taken alone or in combination with green tea and capsaicin; rhubarb, astragalus, red sage, turmeric, and gallic acid (Number Ten); or raspberry ketone (Razberi K, Integrity Nutraceuticals), caffeine, capsicum extract (Capsimax, OmniActive Health Technologies), bitter orange fruit (Advantra Z, Nutratech Inc), L-theanine, and black pepper fruit extract (Biperine, Sabinsa Corporation) (Prograde Metabolism) (20346,20347,40802,96676). Due to the various other ingredients contained in available formulations, any effect from ginger is unclear.
• Parturition. It is unclear if bathing in a ginger bath is beneficial for shortening the duration of labor. Details: Preliminary clinical research shows that bathing in 228 liters of water containing 4 drops of ginger essential oil does not shorten the duration of labor when compared with a regular bath (20345).
• Polycystic ovary syndrome (PCOS). It is unclear if oral ginger is beneficial for females with PCOS. Details: Preliminary clinical research in females with PCOS shows that taking ginger 500 mg three times daily orally for 8 weeks decreases body weight, body mass index, and levels of follicle stimulating hormone and luteinizing hormone, when compared with placebo. It does not affect testosterone levels (110006).
• Postoperative nausea and vomiting (PONV). Evidence for the use of oral ginger for preventing PONV is inconclusive and conflicting. Reasons for the conflicting findings may relate to the ginger formulation used and the outcomes measured. It is unclear if ginger aromatherapy is beneficial for PONV. Details: Some individual clinical studies, as well as a large, recent meta-analysis of the available clinical research, show that taking ginger by mouth 1 hour prior to surgery does not reduce the incidence of 24-hour PONV (3452,3453,17369,99445). Also, the meta-analysis found that, although ginger reduces the severity of PONV when measured on a visual analogue scale (VAS), it does not reduce the severity of PONV when measured on a verbal descriptive scale (VDS). Furthermore, ginger does not reduce the use of rescue antiemetic medications (99445). However, some small, individual clinical studies and a meta-analysis of older clinical research show that taking ginger by mouth prior to surgery reduces the incidence of 24-hour PONV by up to 16% to 38% (722,723,1919,13237,20336,20338,20339). In addition, large clinical trials show that the frequency and severity of PONV 2-6 hours after surgery are similar when ginger 1 gram is given orally or when medications such as metoclopramide or dexmedetomidine are given intravenously prior to undergoing anesthesia (103356,103360). However, taking ginger prior to general anesthesia, in combination with other antiemetics like dexamethasone or cimetidine and metoclopramide, does not seem to reduce nausea and vomiting when compared with the other medications alone (20337,89890). In contrast, other research shows that powdered ginger 1-2 grams 30-60 minutes before induction of anesthesia has been used in most studies showing benefit, occasionally followed by 1 gram of ginger administered two hours after surgery (722,723,13237,20336,20338,103356,103360). Ginger aromatherapy has also been evaluated for the prevention of PONV. Application of 5% ginger essential oil to the wrists of patients prior to the induction of general anesthesia seems to prevent PONV in approximately 80% of treated patients (20334). Also, use of ginger essential oil aromatherapy on a gauze pad results in nausea relief in approximately 67% of patients compared with 40% in the placebo group; however, a blend of essential oils including ginger, spearmint, peppermint, and cardamom, results in nausea relief in 82% of patients (89888).These conflicting findings may be due to differences in outcome measures and the chemical compositions of ginger preparations used in the various clinical studies. Some evidence suggests that the efficacy of ginger for preventing PONV differs based on the formulation used. A network meta-analysis of 18 studies evaluating various ginger preparations, including ginger oil, ginger powder, ginger extract, and a combination of ginger powder and antiemetics, for the prevention of PONV suggests that ginger powder and ginger oil are the most effective formulations for preventing nausea and vomiting, respectively. The analysis also shows that while no ginger formulation is superior to another for the prevention of nausea, ginger powder and ginger oil have a lower risk of postoperative vomiting when compared with ginger extract. A subgroup analysis suggests that ginger seems to be most effective in adults over 30 years of age, when administered preoperatively, and when used for gastrointestinal, hepatobiliary, obstetric, or ophthalmic surgeries (112108).
• Postoperative recovery. It is unclear if oral ginger is beneficial for postoperative recovery. Details: One preliminary clinical study in adults who had a tonsillectomy shows that taking a specific ginger supplement (Solgar, Leonia) 500 mg twice daily for 7 days along with acetaminophen and antibiotics modestly improves pain and wound healing when compared with acetaminophen and antibiotics alone (96674).
• Postpartum complications. It is unclear if oral ginger is beneficial in patients with postpartum pain. Details: A small clinical study in patients recovering from vaginal delivery shows that taking ginger powder 500 mg 8-hours post-delivery, followed by 250 mg every 8 hours thereafter for 24 hours, reduces postpartum pain by nearly 1 point on a 10-point rating scale when compared with placebo (107904). It is unclear if this improvement would be considered clinically relevant.
• Radiation-induced nausea and vomiting. It is unclear if oral ginger is beneficial in patients with radiation-induced nausea and vomiting. Details: A very small study in adults with cervical cancer undergoing treatment with cisplatin and radiotherapy shows that taking ginger 250-500 mg twice daily for 6 weeks in addition to standard antiemetic therapy does not reduce acute or delayed nausea and vomiting when compared with antiemetic therapy alone (113616).
• Rheumatoid arthritis (RA). One small clinical study suggests that oral ginger may improve some symptoms of RA. Details: Preliminary clinical research in adults with RA shows that taking ginger powder 1500 mg daily for 12 weeks improves disease activity on the Disease Activity Score-28 when compared with placebo (100697).
• Smoking cessation. Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A moderate-sized clinical study in adults with a history of smoking 5 or more cigarettes daily for at least 3 years shows that taking a specific combination product containing ginger 25 mg, turmeric, ashwagandha, Indian gooseberry, tribulus, bacopa, Albizia lebbeck, licorice, clove, cowhage, holy basil, and turmeric (Smotect, Smotect India) daily for 3 months reduces the number of cigarettes smoked by approximately 3 per day when compared with placebo. This product also reduces levels of alveolar carbon monoxide and carboxyhemoglobin but does not improve lung capacity (112115). However, only data from patients who completed treatment were analyzed, which limits the validity of this study. It is also unclear if these effects are due to ginger, other ingredients, or the combination.
• Swallowing dysfunction. The effects of oral ginger for treating swallowing dysfunction are inconclusive. Reasons for the conflicting findings may relate to the route of administration or the number of treatments provided. Details: Clinical research shows that applying a spray containing ginger and clematix root (Tongyan) to the oropharynx for 28 days is more effective than placebo at treating grade 2 or 3 dysphagia in stroke victims. However, there does not seem to be a beneficial effect in patients with grade 1 dysphagia (20342). Other clinical research in elderly patients with dysphagia shows that taking a single dose of ginger 2 mg orally does not improve swallowing but increases saliva (96671). It is possible that a single dose of ginger is not enough to improve swallowing function.
• Toxin-induced liver damage. Oral ginger might help to prevent liver damage in patients using antimycobacterial drugs. Details: Preliminary clinical research shows that a specific ginger supplement (Zintoma, Goldaru) 500 mg taken 30 minutes prior to antimycobacterial drugs daily for 4 weeks reduces the percentage of patients experiencing an increase in liver function enzymes to greater than five times the upper limit of normal by 54% when compared with placebo. Antimycobacterial drugs used for tuberculosis in the study included isoniazid 5 mg/kg, rifampin 10 mg/kg, ethambutol 15 mg/kg, and pyrazinamide 25 mg/kg daily (96670).
• Traumatic brain injury (TBI). Oral ginger has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary research in young adults with subjective memory dysfunction associated with mild TBI, shows that taking a combination of ginger 36 mg and boswellia 360 mg (Memoral) every 8 hours orally for one month improves scores for some, but not all, parameters on an auditory-visual learning test performed at one and three months, when compared with placebo. Total learning scores increased by about 7.5 points with the ginger combination product, compared with 4 points for placebo (110132). It is unclear if these effects are due to ginger, boswellia, or the combination.
• Ulcerative colitis. It is unclear if oral ginger is beneficial for improving symptoms of ulcerative colitis. Details: Preliminary clinical research in adults with ulcerative colitis shows that taking ginger powder 1000 mg twice daily for 12 weeks improves disease activity as measured by the Simple Clinical Colitis Activity Index Questionnaire when compared with taking placebo. However, taking ginger did not improve quality of life, stool frequency, bowel distress, or flatulence when compared with placebo (100694). It is possible that this study was not adequately powered to detect a difference in these secondary outcomes.
• Upper respiratory tract infection (URTI). Although there has been interest in using oral ginger for various upper respiratory tract infections, there is insufficient reliable information about the clinical effects of ginger for this condition.
• Vertigo. It is unclear if oral ginger is beneficial for improving symptoms of vertigo. Details: A small clinical study shows that taking 1 gram of ginger orally as a single dose prior to stimulated vertigo seems to reduce symptoms of vertigo, including nausea, when compared with placebo. However, it does not seem to reduce nystagmus (7623). More evidence is needed to rate ginger for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Dyspepsia. Oral olive leaf extract has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small study in healthy adults shows that taking a specific combination product containing olive leaf extract 24% and prickly pear cactus 33% (Mucosave, Bionap S.R.L.) 400 mg daily for 8 weeks seems to improve dyspepsia and other gastrointestinal symptoms when compared with placebo (105904). It is unclear if this benefit would occur in patients with clinically diagnosed dyspepsia.
• Exercise-induced respiratory infections. It is unclear if oral olive leaf extract is beneficial for reducing respiratory infections from exercise. Details: A small clinical study in high school athletes shows that taking one tablet of olive leaf extract providing eleuropein 100 mg daily for 2 months during training season does not reduce the incidence of the common cold when compared with placebo. While it may reduce the number of sick days by 28%, a sub-group analysis suggests that this reduction is only evident in female athletes (101860).
• Gastroesophageal reflux disease (GERD). Although there is interest in using oral olive leaf for GERD, there is insufficient reliable information about the clinical effects of olive for this condition.
• Herpes zoster (shingles). Although there is interest in using oral olive leaf for shingles, there is insufficient reliable information about the clinical effects of olive for this condition.
• Influenza. Although there is interest in using oral olive leaf for influenza, there is insufficient reliable information about the clinical effects of olive for this condition.
• Metabolic syndrome. It is unclear if oral olive leaf extract is beneficial for improving body composition and cardiovascular risk factors in patients with metabolic syndrome. Details: A small clinical trial in overweight, middle-aged males at risk for metabolic syndrome shows that taking four capsules of olive leaf extract providing oleuropein 51.1 mg and hydroxytyrosol 9.7 mg daily for 12 weeks improves insulin sensitivity by 15% when compared with placebo. However, body composition, blood pressure, cholesterol levels, and other cardiovascular risk factors were not improved (92245).
• Osteoarthritis. It is unclear if oral olive fruit or leaf extract is beneficial for improving osteoarthritis. Details: Preliminary clinical research shows that taking a freeze-dried aqueous extract of olive fruit 400 mg daily for 8 weeks decreases pain and increases mobility in people with osteoarthritis (14844). Other preliminary clinical research in adults with knee osteoarthritis shows that taking olive leaf extract 50.1 mg daily for 4 weeks improves overall pain measurements by 14%, compared to only 4% in the placebo group. However, many individual measurements of pain are not improved (92252).
• Osteoporosis. It is unclear if oral olive leaf extract is beneficial for osteoporosis. Details: Clinical research shows that taking olive leaf extract (Bonolive, BioActor BV) 250 mg daily for 12 months, along with elemental calcium 400 mg daily, increases osteocalcin levels by about 32% when compared to baseline; this increase was significant when compared to those taking calcium 400 mg plus placebo, who showed a 6% decrease in osteocalcin levels. However, taking olive leaf extract does not significantly increase bone mineral density of the lumbar spine or femur neck when compared with placebo (92247).
• Rheumatoid arthritis (RA). It is unclear if oral olive fruit extract is beneficial for improving RA symptoms. Details: Preliminary clinical research in adults with RA shows that taking an aqueous freeze-dried extract of olive fruit 400 mg daily for 8 weeks does not improve symptoms when compared with control (14844). More evidence is needed to rate the effectiveness of olive for these uses.

(Read more about OLIVE)

LIKELY EFFECTIVE

• Irritable bowel syndrome (IBS). Oral enteric-coated peppermint oil is conditionally recommended by the American College of Gastroenterology (ACG) for the relief of global IBS symptoms, such as abdominal pain. Details: The ACG conditionally recommends the use of peppermint for the relief of global IBS symptoms. This recommendation is based on an available meta-analysis of generally low-quality clinical research (105124). Several clinical trials and meta-analyses show that taking enteric-coated peppermint oil 1-2 capsules orally two to four times daily reduces abdominal pain, distention, flatulence, and bowel movements in patients with IBS. Each capsule provides approximately 0.2 mL of peppermint oil or 180-225 mg peppermint oil. Most trials have used specific products (Colpermin, Tillotts Pharma; Mintoil, Cadigroup; Ibgard, IM HealthScience, Tempocol) (3802,3803,4469,11778,11779,17681,17682,68467,68515,68522)(68603,68604,68605,96360,99493,109980). The most recent meta-analysis to date shows that four patients would need to take peppermint oil to prevent one patient from having persistent IBS symptoms, and seven patients would need to take peppermint oil to prevent one patient from having abdominal pain. However, the individual studies included in the analysis lasted no more than 12 weeks (109980); any long-term effects are unclear. Although most studies have shown benefit for reducing symptoms, some older studies have found no significant effect (11777,11789) or only short-term benefits (68620). Also, a well-designed study shows that taking peppermint oil capsules designed for either small intestinal release (enteric-coated) or ileocolonic release does not increase the number of people with at least a 30% decrease in abdominal pain over a period of 4 weeks, although symptoms are modestly reduced when compared with placebo (102602). Another clinical trial in patients with moderate to severe IBS shows that taking a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) 180 mg three times daily for 6 weeks does not further improve symptom severity when compared with placebo. However, both groups experienced a large improvement on the IBS-Severity Scoring System (IBS-SSS) and the IBS Global Improvement Scale (107955). The validity of these findings is limited due to lost data and inconsistent follow-up; additionally, adverse effects occurred more frequently in the peppermint oil group. The reasons for these negative findings are unclear but may include short treatment durations and the use of different formulations; additionally, IBS is comprised of various subtypes and symptoms that can range in severity and presentation, which may alter treatment response. Some clinical research has also evaluated a specific combination product (Atrantil, KBS Research) containing peppermint leaf, red quebracho extract, and conker tree extract. Taking this product as needed for 2 weeks seems to reduce constipation and bloating when compared to baseline in patients with constipation-predominant IBS (95429,95430). It is unclear if the effects of this product are due to peppermint, the other ingredients, or the combination.

POSSIBLY EFFECTIVE

• Barium enema-related colonic spasm. Rectal peppermint, as part of barium enema preparations, seems to reduce colonic spasms during examination. Oral peppermint also seems to be beneficial. Details: Rectal use of peppermint oil, added as an ingredient in barium enema preparations, seems to relax the colon during barium enema examination and reduce the percentage of patients who experience colonic spasms by about 25% to 30% (6739,6749,12009). Adding peppermint oil to the barium enema seems to be at least as effective as using systemic scopolamine (Buscopan). Adding peppermint oil to the barium solution also does not seem to impair image quality (12009). Some clinical research also shows that taking peppermint oil orally before the start of a double-contrast barium enema examination decreases spasms and might also increase diagnostic quality (14467).
• Chemotherapy-induced nausea and vomiting (CINV). Oral and inhaled peppermint seem to reduce nausea and vomiting in patients with CINV. Details: Clinical research shows that adding peppermint oil, 40 drops in 20 mL water, every 8 hours following chemotherapy treatment to treatment with standard antiemetics reduces the severity of nausea, vomiting, and anorexia by moderate to large amounts over 48 hours when compared with a plain water placebo (105123). The use of peppermint oil aromatherapy has also been investigated. Clinical research shows that adding 2 drops of peppermint oil to a cool, damp washcloth for use on the neck as aromatherapy for about 30 minutes helps relieve chemotherapy-induced nausea by a small amount when compared with a washcloth without peppermint oil (102603). Additional clinical research in patients receiving standard antiemetics after chemotherapy shows that applying one drop of peppermint oil below the nose three times daily for 5 days reduces the severity of nausea and the frequency of nausea, vomiting, and retching by a moderate to large amount when compared with the antiemetics alone. These parameters were not improved following treatment with cisplatin (105122). A meta-analysis of 3 randomized controlled trials in adults receiving chemotherapy also shows that peppermint oil aromatherapy moderately improves nausea and vomiting when compared with control. However, the results of this analysis are limited by heterogenous application methods, doses, and durations of peppermint therapy (114761). In children with acute leukemia, a small clinical study shows that aromatherapy with 2 drops of peppermint oil and 3 drops of lemon oil in 80 mL of water diffused 30 minutes prior to and 2 and 4 hours after chemotherapy once weekly for 4 weeks decreases the severity of nausea, vomiting, and retching, and improves quality of life scores when compared with diffused water or no intervention (112015). The validity of these findings is limited by the use of patient-reported outcomes. Another small clinical trial in children receiving chemotherapy for acute leukemia shows that aromatherapy with peppermint oil 2%, 0.2 mL inhaled over 3 minutes immediately prior to 3 consecutive chemotherapy sessions, added to standard care (e.g. antiemetic medications), reduces overall incidence of nausea by 40%, and improves nausea and vomiting severity scores, when compared with no additional interventions. These results were similar to those receiving Swedish massage prior to chemotherapy sessions (114759).
• Dyspepsia. Oral peppermint, in combination with caraway and possibly other ingredients, seems to reduce symptoms of dyspepsia. It is unclear if oral peppermint alone is beneficial. Details: Some clinical research shows that taking specific products containing peppermint and caraway oil (Enteroplant, Dr Willmar Schwabe Pharmaceuticals; Menthacarin, Dr Willmar Schwabe GmbH & Co.) improves quality of life and reduces symptoms of dyspepsia, including feelings of fullness, pain, and mild gastrointestinal spasms (6740,6741,10075,96344,102600). A meta-analysis of three of these clinical studies shows that taking this combination product 2-3 times daily for 4 weeks modestly reduces abdominal pain when compared with placebo (110091). Taking this combination twice daily for 4 weeks also improves postprandial distress syndrome and epigastric pain syndrome, two subtypes of dyspepsia, when compared with placebo (96344). The combination of enteric-coated peppermint oil 90 mg and caraway oil 50 mg appears to be comparable to cisapride for relieving dyspepsia when taken 2-3 times daily for up to 4 weeks (6740,6741,10075). However, most trials investigating this combination are small and/or of overall low quality (102600). A specific combination product containing peppermint leaf (Iberogast, Steigerwald Arzneimittelwerk GmbH) also seems to improve symptoms of dyspepsia. The combination includes peppermint leaf plus clown's mustard plant, German chamomile, caraway, licorice, milk thistle, angelica, celandine, and lemon balm (7049). A meta-analysis of studies using this combination product shows that taking 1 mL orally three times daily over a period of 4 weeks reduces the severity of acid reflux, epigastric pain, cramping, nausea, and vomiting when compared with placebo (13089). A similar combination product containing extracts from peppermint leaf, clown's mustard plant, German chamomile flower, caraway, licorice root, and lemon balm (STW 5-II, Steigerwald Arzneimittelwerk GmbH) 1 mL taken three times daily for up to 8 weeks eliminates gastrointestinal symptoms in 40% more dyspepsia patients when compared with placebo (12724).
• Endoscopy-associated adverse effects. Intraluminal peppermint seems to reduce spasticity during an endoscopy. It is unclear if oral peppermint is beneficial for reducing adverse effects related to endoscopy. Details: A meta-analysis of four clinical trials show that peppermint oil, administered orally or intraluminally, reduces the incidence of spasticity by about 41% when compared with placebo in patients undergoing endoscopy, with severe spasticity occurring at about 30% the rate of those taking placebo. However, there was no effect on subjective pain (102604). Individual clinical studies show that intraluminal peppermint oil can reduce both pain and spams in patients undergoing endoscopy (18220,68371,68395,68445,68532). However, there are limitations with this form of administration, including cost and practicality, which has led to interest in the use of oral formulations (104221). Studies evaluating oral extended-release peppermint have been conflicting. While one study shows that a specific extended-release peppermint oil product (Colpermin) 187 mg or 0.2 mL taken orally 4 hours prior to a colonoscopy reduces procedure time, pain, and spasticity (68532), a study using another specific extended-release peppermint oil (IBGard) did not show an effect on colonic spasms, procedure time, or adenoma detection rate when compared with placebo (104221). These differing outcomes may be due to timing of administration. The study that showed benefit administered the treatment 4 hours prior to endoscopy, whereas the study showing no benefit administered the treatment only 1 hour prior. This suggests that extended-release peppermint may need to be administered at least 4 hours prior to the procedure to allow for adequate colonic release (68532,102604,104221).
• Nipple fissures. Topical peppermint seems to reduce cracked skin and pain in the nipples due to breastfeeding. Details: Clinical research shows that topical application of peppermint oil in gel or water reduces cracked skin and pain in the nipple area from breastfeeding when compared with using placebo, lanolin, or the expressed breast milk technique (68454,68462). Other research shows that applying peppermint oil in cream immediately after breastfeeding for 2 weeks decreases pain and trauma in the nipple area similarly to the topical application of dexpanthenol or lanolin (96365).
• Pressure ulcers. Topical peppermint seems to reduce the risk of pressure ulcers. Details: Clinical research in bedridden patients shows that prophylactic application of a topical gel containing peppermint oil 0.2% three times daily for up to 14 days results in pressure injuries in about 23% of patients compared with 77% of those given a placebo gel (102605).
• Tension headache. Topical peppermint seems to relieve tension headaches. Details: Clinical research shows that topical application of peppermint oil 10% relieves tension headaches when compared with placebo (3801,6190).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Abdominal pain. Although there has been interest in using oral peppermint for abdominal pain, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety. Details: A clinical trial in patients presenting to the emergency department for an acute coronary syndrome event shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 1 hour improves anxiety and respiratory rate when compared with baseline or placebo (107958). Due to the single-dose nature of this study, the effects of repeated inhalation of peppermint oil are unclear.
• Athletic performance. It is unclear if oral peppermint oil is beneficial for athletic performance. Details: Preliminary clinical research in trained adult runners shows that taking peppermint essential oil, 0.05 mL diluted in 500 mL of water, orally once 30 minutes before exercise improves running time to exhaustion by 11% when compared with placebo (112742). Another very small clinical study in elite soccer athletes shows that use of a specific peppermint essential oil (doTERRA), 1 drop rubbed into hands and inhaled with 5 deep breaths, does not improve jump performance metrics when compared with placebo (114760).
• Breast cancer-related hot flashes. It is unclear if topical peppermint is beneficial for reducing hot flashes in patients with breast cancer. Details: Preliminary clinical research shows that using a spray containing a combination of peppermint and neroli hydrolat does not alleviate hot flashes in most patients receiving chemotherapy for breast cancer when compared with using a plain water spray (68481).
• Cognitive function. It is unclear if inhaled peppermint oil is beneficial for improving cognitive function. Details: Preliminary clinical research shows that inhalation of peppermint oil slightly improves memory and the performance of cognitive tasks such as typing, alphabetization, and ordering, but not attention and speed of task completion, when compared with control (56954,68416,68466).
• Common cold. Although there has been interest in using oral, topical, or inhaled peppermint for the common cold, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Dental plaque. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth for one minute with 10 mL of a specific combination product (HiOra, Himalaya Herbal Healthcare) containing peppermint oil and numerous other ingredients twice daily for two days reduces plaque index or plaque area when compared with placebo; however, it was not as effective as chlorhexidine 0.2% solution (68530). It is unclear if these effects are due to peppermint oil, other ingredients, or the combination.
• Diffuse esophageal spasm. It is unclear if oral peppermint oil is beneficial for diffuse esophageal spasm. Details: A small exploratory study in adults with diffuse esophageal spasm shows that drinking a solution of peppermint oil, 5 drops in 10 mL of water, can resolve esophageal contractions when compared with baseline (13415). The validity of this finding is limited by the lack of a comparator group.
• Dysmenorrhea. It is unclear if oral peppermint oil is beneficial for reducing menstrual pain. Details: Preliminary clinical research shows that taking three capsules of peppermint oil (Colpermin; Tillotts Company or Razak company) daily for 3 days, starting on the first day of menstruation, is as effective as mefenamic acid 250 mg three times daily for reducing pain, and more effective for reducing nausea and vomiting, associated with dysmenorrhea. However, mefenamic acid was more effective for reducing bleeding and analgesic use (105125).
• Fatigue. It is unclear if inhaled peppermint oil improves fatigue in patients with cardiac disease. Details: A clinical trial in hospitalized patients with various forms of cardiac disease shows that placing 3 drops of peppermint oil on a cotton ball and inhaling for 20 minutes nightly for 7 days improves fatigue scores when compared with placebo. These improvements were similar to those seen with lavender oil inhalation. Fatigue scores decreased by 24 and 21 points in the peppermint and lavender groups, respectively, compared with a 2-point reduction in the placebo group (107959). The validity of these findings is limited due to the short duration of treatment.
• Halitosis. Peppermint has only been evaluated in combination with other ingredients as a mouthwash; its effect when used alone is unclear. Details: Preliminary clinical research shows that rinsing the mouth with a specific combination of tea tree oil, peppermint, and lemon essential oil once for three minutes improves breath smell when compared with placebo or benzydamine hydrochloride (19177). Other preliminary clinical research in elderly adults with dementia who require oral care assistance shows that cleaning the mouth with a mixture of peppermint oil, tea tree oil, and lemon essential oils diluted to 0.5%, applied via gauze, twice daily for 7 days improves halitosis scores and oral condition scores when compared with placebo (112957).
• Insomnia. It is unclear if inhaled peppermint oil is beneficial for insomnia. Details: Preliminary clinical research in cancer patients shows that receiving aromatherapy as three drops of peppermint oil applied to a cotton ball and attached to the collar for 20 minutes at bedtime for one week improves sleep when compared with baseline. However, it seems to be no better than using lavender oil aromatherapy or using a control of lavender oil 1% (103063).
• Menopausal symptoms. It is unclear if inhaled peppermint oil is beneficial for menopausal symptoms. Details: Preliminary clinical research in adults with menopausal symptoms shows that receiving aromatherapy as 2 drops of peppermint oil with upper extremity massage and for 30 minutes twice weekly for 4 weeks moderately improves menopause symptom scores, including both somatic symptoms and urogenital symptoms, when compared with placebo (112745).
• Migraine headache. It is unclear if intranasal or inhaled peppermint oil is beneficial for migraine headache. Details: Preliminary clinical research shows that using 1-2 doses of intranasal peppermint oil 1.5% (Poursina Company) at the start of migraine pain is as effective as intranasal lidocaine 4%, and more effective than placebo, for reducing migraine headache intensity. Approximately 42% of those using peppermint oil indicated a high level of headache reduction, compared with 42% of those using lidocaine and 5% of those using placebo. Also, pain relief was felt within 5 minutes in more patients using peppermint than placebo (105126). However, it is unclear if participants were truly blinded to the use of peppermint oil. Other preliminary clinical research in pediatric patients with migraine or other chronic headaches shows that receiving aromatherapy with peppermint oil over 10 minutes during a footbath does not improve pain or anxiety scores when compared with control (112746).
• Mosquito repellent. Although there has been interest in using topical peppermint oil as a mosquito repellent, there is insufficient reliable information about the clinical effects of peppermint for this purpose.
• Myalgia. Although there has been interest in using topical peppermint oil for myalgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Oral mucositis. Topical peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in adults undergoing stem cell transplantation shows that using an oral rinse containing peppermint oil and German chamomile three times daily, in addition to standard treatment with sodium chloride and chlorhexidine, reduces the duration and severity of mucositis and the use of narcotic analgesics when compared with placebo and standard treatment. However, this oral rinse does not reduce or delay the occurrence of mucositis or affect the duration of hospitalization (96363). Another small clinical study in adults with head and neck cancers undergoing radiation shows that rinsing with 5 mL of a polyherbal mouthwash containing peppermint oil, German chamomile, aloe vera, and honey for 1 minute 3 times daily for 6 weeks reduces oral mucositis incidence, severity, and pain when compared with chlorhexidine 0.2% and placebo (111291). Clinical research in adults receiving treatment with 5-fluorouracil shows that using an oral rinse containing peppermint, sage tea, and thyme in addition to basic oral care, starting on the first day of chemotherapy and continuing for 14 days, delays the onset of mucositis, but not the rate or severity of mucositis, when compared with basic oral care alone (96364). It is unclear if these effects are due to peppermint oil, other ingredients, or the combinations.
• Osteoarthritis. Although there has been interest in using topical peppermint oil for osteoarthritis, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Pain (acute). It is unclear if inhaled or topical peppermint oil is beneficial for acute pain. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy reduces pain associated with intravenous catheterization by a small amount when compared with a distilled water control (102601). Another small open-label study in adults undergoing venipuncture for dialysis shows that topical application of peppermint gel 5 mL reduces pain scores by approximately 50% when compared with no intervention. These results were similar to using a cold compress (114758). Additionally, a small open-label study in children undergoing a dental procedure, shows that topical application of peppermint oil 0.2% , moderately improves pain scores after a buccal injection when compared with lidocaine spray 15% (114757).
• Postherpetic neuralgia. Although there has been interest in using topical peppermint oil for postherpetic neuralgia, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Postoperative ileus. It is unclear if oral peppermint oil is beneficial for the prevention of postoperative ileus. Details: Clinical research shows that taking a specific peppermint oil product (Colpermin, Tillotts Pharma) as two capsules three times daily for 5 days after routine gynecological surgery does not prevent postoperative abdominal distension and dyspepsia when compared with placebo (68602). Conversely, a small clinical study in patients undergoing elective cesarean section shows that taking 20 drops of peppermint oil 4 hours after surgery and then hourly for a total of three doses reduces the time to first bowel sounds by around 3.3 hours, first flatulence by 4.4 hours, and first stool by 5 hours when compared with placebo (110092).
• Postoperative nausea and vomiting (PONV). Some preliminary clinical studies suggest that inhaled peppermint may be beneficial for PONV. However, it is unclear if the benefit is due to aromatherapy or improved breathing patterns. Details: Some preliminary clinical research shows that using peppermint aromatherapy helps relieve postoperative nausea (3804,13415,68524,104219,104220). Inhaling peppermint oil 10% and 30% as aromatherapy reduces the severity of nausea when compared with placebo, with no significant difference between concentrations (104220). Small clinical trials show improvement in PONV within the first 4 hours after surgery. However, this effect diminishes beyond 4 hours (104219). Other preliminary clinical research shows that peppermint oil aromatherapy is no more effective for reducing postoperative nausea than inhaling isopropyl alcohol or saline (13416,68529). It is possible that any relief of postoperative nausea observed with peppermint aromatherapy results from improved breathing patterns after surgery rather than peppermint oil itself (13416,90512). One small study shows that inhaling peppermint oil while practicing controlled breathing does not appear to relieve PONV better than practicing controlled breathing alone (90512). Some preliminary clinical research shows that inhaling vapors from a mixture of peppermint, ginger, spearmint, and cardamom essential oils reduces symptoms of postoperative nausea in approximately 15% more patients when compared with inhaling ginger essential oils alone, and in approximately 43% more patients when compared with inhaling saline (89888). However, it is not clear if the effect is due to peppermint, the other oils, or the combination. In contrast, a small clinical trial in adults undergoing port catheter placement shows that application of a specific aromatherapy patch containing peppermint and lavender (Elequil Aromatabs, Beekley Medical) preoperatively does not reduce PONV rescue treatment when compared with placebo (114623). Another small clinical trial in adults with anxiety undergoing total hip or knee arthroplasty shows that application of the same patch containing peppermint and lavender every 12 hours for 6 doses does not reduce overall PONV when compared with placebo (114622).
• Postoperative pain. It is unclear if inhaled peppermint oil is beneficial for postoperative pain. Details: Preliminary clinical research in adults undergoing open heart cardiac surgery shows that receiving aromatherapy with peppermint oil 10%, 0.1 mL, three times daily for 7 doses moderately improves pain scores when compared with placebo (112747). Other preliminary clinical research in adults undergoing lumbar discectomy surgery shows that receiving aromatherapy with peppermint oil 5 drops once postoperatively modestly improves pain scores and anxiety scores when compared with no intervention (112744). A small clinical trial in adults undergoing port catheter placement shows that application of a specific aromatherapy patch containing peppermint and lavender (Elequil Aromatabs, Beekley Medical) preoperatively does not improve pain scores or reduce opioid rescue treatment in the immediate post-operative period when compared with placebo (114623). Another small clinical trial in adults with anxiety undergoing total hip or knee arthroplasty shows that application of the same patch containing peppermint and lavender every 12 hours for 6 doses modestly reduceses opioid consumption on postoperative day 2, but not day 1, 7, or 30, when compared with placebo (114622). However, these changes are unlikely to be clinically relevant. In addition, it is unclear if any potential effects are due to peppermint, lavender, or the combination.
• Postoperative recovery. Inhaled peppermint has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in adults undergoing port catheter placement shows that application of a specific aromatherapy patch containing peppermint and lavender (Elequil Aromatabs, Beekley Medical) preoperatively does not shorten postoperative length of stay when compared with placebo (114623).
• Postoperative sleep disturbance. It is unclear if inhaled peppermint oil is beneficial for postoperative sleep disturbance. Details: Preliminary clinical research in adults undergoing open heart cardiac surgery shows that receiving aromatherapy with peppermint oil 10%, 0.1 mL, three times daily for 7 doses modestly improves sleep scores when compared with placebo (112747).
• Pre-procedural anxiety. It is unclear if inhaled peppermint oil is beneficial for reducing anxiety prior to a medical procedure. Details: Preliminary clinical research in cardiac patients shows that peppermint oil aromatherapy does not reduce anxiety associated with intravenous catheterization when compared with a distilled water control (102601).
• Pregnancy-induced nausea and vomiting. Inhaled peppermint oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research shows that aromatherapy with a mixture of 5% lemon and 5% peppermint essential oils modestly reduces the intensity of nausea and vomiting on days 2-4, but not day 1, when compared with placebo aromatherapy. When nauseated, patients placed three drops of the essential oil mixture (Barij Essence Co.) onto a cotton ball held 3 cm from the nose. This action could be repeated after 5 minutes if needed (105121).
• Pruritus. Some preliminary clinical studies suggest that topical peppermint oil improves itching of various etiologies. Details: Preliminary clinical research in adults with renal, hepatic, or diabetic pruritus shows that topical application of peppermint oil 5% in petrolatum twice daily for 2 weeks improves symptoms of pruritus when compared with petrolatum alone (96361). Preliminary clinical research in patients with severe or intractable pruritus secondary to burn scars shows that applying a specific product (Chongqing No.1, CQ-01, MJ Medical Gel Systems Ltd.) containing peppermint oil 3.6%, menthol 1.4%, and methyl salicylate 2.5%, covered with gauze for 24 hours, reduces the severity of pruritus for up to 7 days after application when compared with hydrogel covered with gauze or with gauze alone (96362). Preliminary clinical research in females experiencing itchy skin due to intrahepatic cholestasis of pregnancy also shows that applying peppermint oil 0.5% in sesame oil twice daily for 2 weeks reduces pruritus severity approximately 1.8-fold when compared with sesame oil alone (89478).
• Small intestinal bacterial overgrowth (SIBO). Although there has been interest in using oral peppermint for SIBO, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Stress. It is unclear if inhaled peppermint oil is beneficial for stress. Details: Clinical research shows that peppermint aromatherapy decreases physical and perceived levels of stress when compared with baseline (68422,68517). A small clinical study in adults undergoing a virtual reality (VR) driving scenario to test road rage shows that exposure to peppermint oil (Pure Essential Oil of Peppermint, Tisserand Aromatherapy) 5 drops via fan diffuser improves aggressive driving behavior scores but does not seem to improve self-reported stress, aggression, alertness, happiness, or calmness when compared with controls that did not receive aromatherapy during the VR session (112017).
• Toothache. Although there has been interest in using topical peppermint oil for toothache, there is insufficient reliable information about the clinical effects of peppermint for this condition.
• Urticaria. Although there has been interest in using topical peppermint oil for urticaria, there is insufficient reliable information about the clinical effects of peppermint for this condition. More evidence is needed to rate peppermint for these uses.

(Read more about PEPPERMINT)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Lice. Preliminary clinical research shows that a single application of quassia tincture can kill head lice. However, the single application of quassia tincture resulted in 0.6% reinfestation rate after a week (17492). Researchers suggest that two applications with a one-week interval between them might be more effective.
• Rosacea. Preliminary clinical research in patients with rosacea shows that applying quassia 4% gel twice daily for 45 days reduces flushing, redness, and telangiectasia by approximately 74%, 56%, and 50%, respectively, compared with baseline. A moderate to complete overall improvement occurred in 89% of patients (99995). The validity of these results is limited by a lack of control group.
• Seborrheic dermatitis. Preliminary clinical research shows that applying quassia 4% gel twice daily for 28 days results in complete remission in 29.4% of patients with seborrheic dermatitis. This response rate is higher than the 5.6% and 7.1% response rate for patients using 1% ciclopirox olamine or 2% ketoconazole. At one-month post-treatment, quassia was more effective than the other two treatments for avoiding relapse (99994). However, the lack of placebo group makes conclusions difficult. More evidence is needed to rate quassia for these uses.

(Read more about QUASSIA)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Allergic rhinitis (hay fever). Although there has been interest in using oral rooibos for allergic rhinitis, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Age-related cognitive decline. Although there has been interest in using oral rooibos for age-related cognitive decline, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Anxiety. Although there has been interest in using oral rooibos for anxiety, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Cardiovascular disease (CVD). Although there has been interest in using oral rooibos for CVD, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Cancer. Although there has been interest in using oral rooibos for cancer, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Diabetes. Although there has been interest in using oral rooibos for diabetes, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Dyspepsia. Although there has been interest in using oral rooibos for dyspepsia, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• HIV/AIDS. Although there has been interest in using oral rooibos for HIV/AIDS, there is insufficient reliable information about the clinical effects of rooibos for this purpose.
• Obesity. Although there has been interest in using oral rooibos for obesity, there is insufficient reliable information about the clinical effects of rooibos for this purpose. More evidence is needed to rate rooibos for these uses.

(Read more about ROOIBOS)

POSSIBLY EFFECTIVE

• Allergic rhinitis (hay fever). Sweet Annie sublingual immunotherapy drops seem to be beneficial for preventing or reducing seasonal allergic rhinitis and rhinoconjunctivits symptoms related to Sweet Annie (Artemisia annua) pollen. Details: A large clinical study in adults with Artemisia annua (Sweet Annie) pollen-induced seasonal allergic rhinitis shows that taking sublingual drops of a glycerinated allergen extract of Sweet Annie for 32 weeks, beginning 4 months prior to pollen season, improves combined symptom and rescue medication use scores by 22% when compared with placebo. However, in this study the beneficial effects of Sweet Annie appear to be limited to patients mono-sensitized to its pollen; there was no significant improvement in patients who were also sensitized to other pollens (106441). A smaller clinical study shows that taking these drops beginning as early as 8-9 weeks pre-pollen season modestly improves both symptom and rescue medication scores when compared to a control group receiving only symptomatic drugs. In this study, the beneficial effects occurred in patients mono-sensitized to Artemisia pollen, as well as those patients who were also sensitized to other pollens (109315). The validity of this study is limited by the lack of blinding and placebo-control. A small open-label clinical study in adults with confirmed sensitization to Artemisia annua (Sweet Annie) pollen and a history of seasonal allergic rhinoconjunctivitis shows that taking standardized Sweet Annie sublingual immunotherapy drops combined with pharmacotherapy for a year before allergy season improves rhinoconjunctivitis symptoms and rescue medication use during allergy season when compared with pharmacotherapy alone (112392). Two additional open-label studies also show that Sweet Annie sublingual immunotherapy, given for up to 16 months, improves rhinoconjunctivitis symptoms and rescue medication use for up to 2 allergy seasons when compared with control in individuals who are mono-sensitized to Sweet Annie and in those who are poly-sensitized to Sweet Annie plus a variety of other pollen allergens (112393,112394). All of the aforementioned studies were conducted in China where Sweet Annie is the primary outdoor pollen responsible for seasonal allergic rhinitis and rhinoconjunctivitis (106441,109315,112392,112393,112394). As a result, the applicability of the findings to other geographical regions may be limited.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Malaria. It is unclear if Sweet Annie is beneficial for malaria. Details: Some research shows that consuming Sweet Annie tea orally for 4-7 days might improve symptoms and decrease parasite load in patients with malaria (11055,11058). The Sweet Annie constituent artemisinin is of interest for its antimalarial activity, possibly by inactivating the parasite (3185,11056,11057,11059). Derivatives of the artemisinin constituent are occasionally used as medication in combination with other antimalarial compounds (103258). However, there is some concern that using Sweet Annie tea itself as monotherapy may lead to poor long-term outcomes, as well as resistance to artemisinin derivatives (11055,11059).
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if Sweet Annie is beneficial for NAFLD. Details: A clinical study in adults with borderline and mild NAFLD shows that taking an aqueous extract of Sweet Annie 686 mg twice daily for 8 weeks reduces alanine aminotransferase (ALT) concentrations from baseline by a mean of 16 units/L, compared with a reduction of 7 units/L in the placebo group. Aspartate aminotransferase (AST) concentrations and fatigue scores were also improved in those receiving Sweet Annie (106442). However, there have also been reports of liver toxicity with Sweet Annie (16895,103254,103255).
• Osteoarthritis. It is unclear if Sweet Annie is beneficial for osteoarthritis. Details: One small clinical study shows that taking a specific Sweet Annie extract (Arthrem, Promissia Limited) 150 mg twice daily for 12 weeks reduces pain and stiffness and improves function when compared to baseline in patients with osteoarthritis of the hip or knee. However, taking this same extract at a dose of 300 mg twice daily did not produce the same effects (94521). In an extension of this study, the therapeutic effects of taking Sweet Annie 150 mg twice daily were maintained for 6 additional months (94520). However, the validity of these results is limited due to a lack of statistical comparison between the Sweet Annie and placebo groups.
• Rheumatoid arthritis (RA). It is unclear if Sweet Annie is beneficial for RA. Details: Preliminary clinical research in patients with RA shows that taking Sweet Annie 30 grams in warm water once daily for 48 weeks in combination with leflunomide and methotrexate modestly reduces pain, swelling, and tenderness in the joints and increases the cessation of corticosteroids when compared with leflunomide and methotrexate alone (109318). The validity of this study is limited by the lack of a placebo or adequate blinding. More evidence is needed to rate Sweet Annie for these uses.

(Read more about SWEET ANNIE)

LIKELY SAFE ...when the fruit (nut) is consumed in amounts normally found in food.

POSSIBLY UNSAFE ...when the bark is used orally or topically, due to its juglone content (2). When applied topically, juglone-containing bark can cause skin irritation. When used orally on a daily basis, the juglone-containing bark of a related species (English walnut) is associated with increased risk of tongue cancer and lip leukoplakia (2,12). There is insufficient reliable information available about the safety of the leaf or hull when used orally as a medicine or when applied topically.

PREGNANCY AND LACTATION: LIKELY SAFE
when the fruit (nut) is consumed in amounts normally found in foods.

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when the bark is used orally or topically (12); avoid using. There is insufficient reliable information available about the safety of black walnut leaf or hull when used orally in medicinal amounts during pregnancy or lactation; avoid using.

(Read more about BLACK WALNUT)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Clove, clove oil, and eugenol have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912).

POSSIBLY SAFE ...when clove oil is applied topically (272). A clove oil 1% cream has been applied to the anus with apparent safety for up to 6 weeks (43487). A liposome-based product containing clove oil 45% has been applied to the palms with apparent safety for up to 2 weeks (100596).

LIKELY UNSAFE ...when clove smoke is inhaled. Smoking clove cigarettes can cause respiratory injury (17,43599). ...when clove oil is injected intravenously. This can cause pulmonary edema, hypoxemia, and acute dyspnea (16384). There is insufficient reliable information available about the safety of using clove orally in medicinal amounts.

CHILDREN: LIKELY UNSAFE
when clove oil is taken orally. Ingesting 5-10 mL of undiluted clove oil has been linked to reports of coagulopathy, liver damage, and other serious side effects in infants and children up to 3 years of age (6,17,43385,43395,43419,43457,43652).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts found in foods (4912). Clove, clove oil, and eugenol have Generally Recognized As Safe (GRAS) status for use in foods in the US (4912). There is insufficient reliable information available about the safety of using clove in medicinal amounts during pregnancy and lactation; avoid using.

(Read more about CLOVE)

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts (12).

POSSIBLY UNSAFE ...when used orally in large amounts. Elecampane can cause gastrointestinal upset and symptoms of paralysis (12).

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally (12); avoid using.

(Read more about ELECAMPANE)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Fennel has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when fennel essential oil or extract is used orally and appropriately, short-term. Twenty-five drops (about 1.25 mL) of fennel fruit extract standardized to fennel 2% essential oil has been safely used four times daily for 5 days (49422). Also, two 100 mg capsules each containing fennel 30% essential oil standardized to 71-90 mg of anethole has been safely used daily for 8 weeks (97498). Powdered fennel extract has been used with apparent safety at a dose of 800 mg daily for 2 weeks (104199). ...when creams containing fennel 2% to 5% are applied topically (49429,92509).

CHILDREN: POSSIBLY SAFE
when combination products containing fennel are used to treat colic in infants for up to one week. Studied products include up to 20 mL of a fennel seed oil emulsion; a specific product (ColiMil) containing fennel 164 mg, lemon balm 97 mg, and German chamomile 178 mg; and up to 450 mL of a specific tea (Calma-Bebi, Bonomelli) containing fennel, chamomile, vervain, licorice, and lemon balm (16735,19715,49428).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Observational research has found that regular use of fennel during pregnancy is associated with shortened gestation (100513).

LACTATION: POSSIBLY UNSAFE
when used orally. Case reports have linked consumption of an herbal tea containing extracts of fennel, licorice, anise, and goat's rue to neurotoxicity in two breast-feeding infants. The adverse effect was attributed to anethole, a constituent of fennel and anise (16744). However, levels of anethole were not measured in breastmilk, and the herbal tea was not tested for contaminants. Furthermore, other adverse effects related to use of fennel during lactation have not been reported. However, until more is known, avoid using.

(Read more about FENNEL)

LIKELY SAFE ...when the root preparations are used in amounts commonly found in foods. Gentian root is categorized by the FDA as a safe food additive flavoring in the US (4912).

POSSIBLY SAFE ...when gentian root is used orally in a specific combination that contains gentian root, elderflower, verbena, cowslip flower, and sorrel (SinuComp, Sinupret) (374,379,95907). There is insufficient reliable information available about the safety of the topical use of gentian.

PREGNANCY AND LACTATION:
There is insufficient reliable information available about the safety of gentian in medicinal amounts during pregnancy and lactation; avoid using.

(Read more about GENTIAN)

LIKELY SAFE ...when used orally and appropriately. Ginger has been safely used in multiple clinical trials (721,722,723,5343,7048,7084,7085,7400,7623,11346)(12472,13080,13237,13244,17369,17928,17929,89889,89890,89894)(89895,89898,89899,90102,96252,96253,96259,96260,96669) (101760,101761,101762,103359,107903).

POSSIBLY SAFE ...when used topically and appropriately, short-term (89893,89897).

CHILDREN: LIKELY SAFE
when consumed in the amounts typically found in foods.

CHILDREN: POSSIBLY SAFE
when used orally and appropriately, short-term. Ginger powder has been used with apparent safety at a dose of up to 750 mg daily for 4 days in girls aged 14-18 years (96255).

PREGNANCY: LIKELY SAFE
when consumed in the amounts typically found in foods. Ginger is considered a first-line nonpharmacological treatment option for nausea in pregnancy by the American College of Obstetrics and Gynecology (ACOG) (111601). However, it should not be used long-term or without medical supervision and close monitoring.

PREGNANCY: POSSIBLY SAFE
when used for medicinal purposes. Despite some early reports of adverse effects (721,7083) and one observational study suggesting that taking dried ginger and other herbal supplements during the first 20 weeks of pregnancy marginally increased the chance of stillbirth (96254), most research shows that ginger is unlikely to cause harm to the baby. The risk for major malformations in infants of parents who took ginger when pregnant does not appear to be higher than the baseline rate of 1% to 3% (721,1922,5343,11346,13071,13080,96254). Also, other research suggests that ginger intake during various trimesters does not significantly affect the risk of spontaneous abortion, congenital malformations, stillbirth, perinatal death, preterm birth, low birth weight, or low Apgar scores (18211,90103). Ginger use has been associated with an increase in non-severe vaginal bleeding, including spotting, after week 17 of pregnancy (18211).

LACTATION: LIKELY SAFE
when consumed in the amounts typically found in foods. There is insufficient reliable information available about the safety of ginger when used for medicinal purposes; avoid amounts greater than those found in foods.

(Read more about GINGER)

LIKELY SAFE ...when olive fruit is used orally and appropriately in amounts commonly found in foods.

POSSIBLY SAFE ...when olive leaf extract is used orally and appropriately. Olive leaf extract providing 51-100 mg oleuropein daily has been used with apparent safety for 6-8 weeks (92245,92247,101860). There is insufficient reliable information available about the safety of olive fruit extract when used in amounts greater than those found in foods.

PREGNANCY AND LACTATION:
Insufficient reliable information available; stick with amounts commonly found in foods.

(Read more about OLIVE)

LIKELY SAFE ...when peppermint oil is used orally, topically, or rectally in medicinal doses. Peppermint oil has been safely used in multiple clinical trials (3801,3804,6190,6740,6741,10075,12009,13413,14467,17681)(17682,68522,96344,96360,96361,96362,96363,96364,96365,99493).

POSSIBLY SAFE ...when peppermint leaf is used orally and appropriately, short-term. There is some clinical research showing that peppermint leaf can be used safely for up to 8 weeks (12724,13413). The long-term safety of peppermint leaf in medicinal doses is unknown. ...when peppermint oil is used by inhalation as aromatherapy (7107). There is insufficient reliable information available about the safety of using intranasal peppermint oil.

CHILDREN: POSSIBLY SAFE
when used orally for medicinal purposes. Enteric-coated peppermint oil capsules have been used with apparent safety under medical supervision in children 8 years of age and older (4469).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally in amounts commonly found in foods (96361). There is insufficient information available about the safety of using peppermint in medicinal amounts during pregnancy or lactation; avoid using.

(Read more about PEPPERMINT)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Quassia has Generally Recognized as Safe (GRAS) status in the US (4912).

POSSIBLY SAFE ...when used topically and appropriately. A 4% quassia gel has been safely used twice daily for up to 45 days (99995).

POSSIBLY UNSAFE ...when used orally in medicinal amounts. Quassia wood contains cardioactive glycosides (4), but toxicity is likely limited by emetic effects of large doses (4). There is insufficient reliable information available about the safety of rectal use of quassia.

PREGNANCY AND LACTATION: LIKELY UNSAFE
when used orally; avoid using. Quassia has cytotoxic and emetic properties (4,18,19). There is insufficient reliable information available about the safety of rectal or topical use during pregnancy or lactation; avoid using.

(Read more about QUASSIA)

LIKELY SAFE ...when used orally in food amounts (6,4120). There is insufficient reliable information available about the safety of rooibos when used orally in medicinal amounts.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about ROOIBOS)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Sweet Annie 300 mg daily has been used with apparent safety in studies lasting up to 9 months (11055,94520,94521). Sweet Annie tea, prepared from dried leaves and twigs and consumed in divided doses daily, has been used with apparent safety for up to 7 days (11055,11058). While rare, there is some concern that Sweet Annie might cause liver damage (16895,103254,103255).

POSSIBLY SAFE ...when used sublingually and appropriately, short-term. Sweet Annie up to 2400 biological units daily as sublingual immunotherapy has been used with apparent safety in studies lasting up to 16 months (106441,112392,112393,112394). There is insufficient reliable information available about the safety of Sweet Annie when used topically.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

(Read more about SWEET ANNIE)

(Read more about BLACK WALNUT)

CNS DEPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use with drugs with sedative properties may cause additive effects and side effects.  Details Clinical and animal research shows that catnip has sedative properties (19,2596,40202,40204,40205).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, catnip might reduce excretion and increase levels of lithium.  Details Catnip is thought to have diuretic properties which might reduce lithium excretion. The dose of lithium might need to be decreased.

(Read more about CATNIP)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, clove oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.  Details Laboratory research suggests that eugenol, a constituent of clove, has antiplatelet activity (12889,43558,43650,43654). This interaction has not been reported in humans.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of clove extracts with antidiabetes drugs might increase the risk of hypoglycemia.  Details Clinical and laboratory research suggest that polyphenol extracts from clove flower buds might lower blood glucose levels (100595). Dosing adjustments for insulin or oral hypoglycemic agents may be necessary when taken with clove. Monitor blood glucose levels closely.

IBUPROFEN (Advil, others) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, topical application of clove oil with ibuprofen might increase the absorption and side effects of topical ibuprofen.  Details Laboratory research shows that topical application of clove oil increases the absorption of topical ibuprofen (98854). This interaction has not been reported in humans.

(Read more about CLOVE)

CNS DEPRESSANTS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, elecampane may cause additive sedative effects when taken with CNS depressants.  Details Elecampane might have sedative effects (4).

(Read more about ELECAMPANE)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fennel might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.  Details Animal research suggests that fennel oil has antithrombotic and antiplatelet effects (31415,49445).

CIPROFLOXACIN (Cipro) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, fennel might decrease the levels and clinical effects of ciprofloxacin.  Details Animal research shows that fennel reduces ciprofloxacin bioavailability by nearly 50%, possibly due to the metal cations such as calcium, iron, and magnesium contained in fennel. This study also found that fennel increased tissue distribution and slowed elimination of ciprofloxacin (6135).

CONTRACEPTIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might decrease the effects of contraceptive drugs due to competition for estrogen receptors.  Details Some constituents of fennel have estrogenic activity (11).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, fennel might increase levels of drugs metabolized by CYP3A4.  Details In vitro research suggests that fennel inhibits CYP3A4 enzyme activity (38375,49468). This effect has not been reported in humans.

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might interfere with hormone replacement therapy due to competition for estrogen receptors.  Details Some constituents of fennel have estrogenic activity (11).

TAMOXIFEN (Nolvadex) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking large amounts of fennel might decrease the antiestrogenic effect of tamoxifen.  Details Some constituents of fennel have estrogenic activity (11), which may interfere with the antiestrogenic activity of tamoxifen.

(Read more about FENNEL)

ANTIHYPERTENSIVE DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking gentian with antihypertensive drugs might increase the risk of hypotension.  Details In vitro research shows that gentian can cause vasodilation and lower blood pressure (13439,13441).

(Read more about GENTIAN)

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Ginger may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs. However, research is conflicting.  Details Laboratory research suggests that ginger inhibits thromboxane synthetase and decreases platelet aggregation (7622,12634,20321,20322,20323,96257). However, this has not been demonstrated unequivocally in humans, with mixed results from clinical trials (96257). Theoretically, excessive amounts of ginger might increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking ginger with antidiabetes drugs might increase the risk of hypoglycemia.  Details Animal and human research suggests that ginger might increase insulin levels and/or decrease blood glucose levels (12636,20402,20403,20404,20405,89895,89896,107898).

CALCIUM CHANNEL BLOCKERS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, taking ginger with calcium channel blockers might increase the risk of hypotension.  Details Some animal and in vitro research suggests that ginger has hypotensive and calcium channel-blocking effects (12633). Another animal study shows that concomitant administration of ginger and the calcium channel blocker amlodipine leads to greater reductions in blood pressure when compared with amlodipine alone (107901).

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, when taken prior to cyclosporine, ginger might decrease cyclosporine levels.  Details In an animal model, ginger juice taken 2 hours prior to cyclosporine administration reduced the maximum concentration and area under the curve of cyclosporine by 51% and 40%, respectively. This effect was not observed when ginger juice and cyclosporine were administered at the same time (20401).

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, ginger might increase the levels of CYP1A2 substrates.  Details In vitro research shows that ginger inhibits CYP1A2 activity (111544). However, this interaction has not been reported in humans.

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, ginger might increase the levels of CYP2B6 substrates.  Details In vitro research shows that ginger inhibits CYP2B6 activity (111544). However, this interaction has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, ginger might increase the levels of CYP2C9 substrates.  Details In vitro research shows that ginger inhibits CYP2C9 activity (111544). However, this interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Ginger might increase or decrease the levels of CYP3A4 substrates.  Details In vitro research and some case reports suggest that ginger inhibits CYP3A4 activity (111544,111644). Three case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking ginger and cancer medications that are CYP3A4 substrates (imatinib, dabrafenib, and crizotinib). However, the causality of this interaction is unclear due to the presence of multiple interacting drugs and routes of administration (111644). Conversely, other in vitro research suggests that ginger induces CYP3A4 activity, leading to reduced levels of CYP3A4 substrates (111404). However, this interaction has not been reported in humans.

LOSARTAN (Cozaar) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, ginger might increase levels of losartan and the risk of hypotension.  Details In animal research, ginger increased the levels and hypotensive effects of a single dose of losartan (102459). It is not clear if ginger alters the concentration or effects of losartan when taken continuously. Additionally, this interaction has not been shown in humans.

METRONIDAZOLE (Flagyl) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, ginger might increase levels of metronidazole.  Details In an animal model, ginger increased the absorption and plasma half-life of metronidazole. In addition, the elimination rate and clearance of metronidazole was significantly reduced (20350).

NIFEDIPINE (Procardia) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Ginger may have antiplatelet effects and increase the risk of bleeding if used with nifedipine.  Details Clinical research shows that combined treatment with ginger 1 gram plus nifedipine 10 mg significantly inhibits platelet aggregation when compared to nifedipine or ginger alone (20324).

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Ginger might increase the absorption and blood levels of P-glycoprotein (P-gp) substrates.  Details In vitro research and case reports suggest that ginger inhibits drug efflux by P-gp, potentially increasing absorption and serum levels of P-gp substrates (111544,111644). Two case reports from the World Health Organization (WHO) adverse drug reaction database describe increased toxicity in patients taking ginger and cancer medications that are P-gp substrates (trametinib, crizotinib). However, the causality of this interaction is unclear due to the presence of multiple interacting drugs and routes of administration (111644).

PHENPROCOUMON (Marcoumar, others) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Ginger might increase the risk of bleeding with phenprocoumon.  Details Phenprocoumon, a warfarin-related anticoagulant, might increase the international normalized ratio (INR) when taken with ginger. There is one case report of a 76-year-old woman with a stable INR on phenprocoumon that increased to greater than 10 when she began consuming dried ginger and ginger tea (12880).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Ginger might increase the risk of bleeding with warfarin.  Details Laboratory research suggests that ginger might inhibit thromboxane synthetase and decrease platelet aggregation (7622,12634,20321,20322,20323). In one case report, ginger increased the INR when taken with phenprocoumon, which has similar pharmacological effects as warfarin (12880). In another case report, ginger increased the INR when taken with a combination of warfarin, hydrochlorothiazide, and acetaminophen (20349). A longitudinal analysis suggests that taking ginger increases the risk of bleeding in patients taking warfarin for at least 4 months (20348). However, research in healthy people suggests that ginger has no effect on INR, or the pharmacokinetics or pharmacodynamics of warfarin (12881,15176). Until more is known, monitor INRs closely in patients taking large amounts of ginger.

(Read more about GINGER)

(Read more about OLIVE)

CYCLOSPORINE (Neoral, Sandimmune) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint oil might increase the levels and adverse effects of cyclosporine.  Details In animal research, peppermint oil inhibits cyclosporine metabolism and increases cyclosporine levels. Inhibition of cytochrome P450 3A4 (CYP3A4) may be partially responsible for this interaction (11784). An interaction between peppermint oil and cyclosporine has not been reported in humans.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, peppermint might increase the levels of CYP1A2 substrates.  Details In vitro and animal research shows that peppermint oil and peppermint leaf inhibit CYP1A2 (12479,12734). However, in clinical research, peppermint tea did not significantly affect the metabolism of caffeine, a CYP1A2 substrate. It is possible that the 6-day duration of treatment may have been too short to identify a difference (96359).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint might increase the levels of CYP2C19 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C19 (12479). So far, this interaction has not been reported in humans.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, peppermint might increase the levels of CYP2C9 substrates.  Details In vitro research shows that peppermint oil inhibits CYP2C9 (12479). So far, this interaction has not been reported in humans.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, peppermint might increase the levels of CYP3A4 substrates.  Details Clinical research in healthy volunteers shows that a single dose of peppermint oil 600 mg inhibits CYP3A4 enzymes and increases the AUC of felodipine, a CYP3A4 substrate (11783). However, in vitro research suggests that peppermint oil only inhibits CYP3A4 at very high concentrations (12479).

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D In animals, quassia extract reduced levels of fasting glucose (99998). Theoretically, quassia might have additive effects when used with antidiabetes drugs. This might increase the risk of hypoglycemia in some patients. Monitor blood glucose levels closely.  Details Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Overuse of quassia might compound diuretic-induced potassium loss (13). There is some concern that people taking quassia along with potassium depleting diuretics might have an increased risk for hypokalemia. Initiation of potassium supplementation or an increase in potassium supplement dose may be necessary for some patients.  Details Some diuretics that can deplete potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), and hydrochlorothiazide (HCTZ, Hydrodiuril, Microzide), and others.

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ACE INHIBITORS (ACEIs) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with ACEIs may increase the therapeutic and adverse effects of ACEIs.  Details Clinical research in healthy adults shows that taking a single dose of rooibos tea, 400 mL orally, inhibits angiotensin-converting enzyme activity (101253).

ATORVASTATIN (Lipitor) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with atorvastatin may increase the therapeutic and adverse effects of atorvastatin.  Details Animal research shows that consuming green rooibos extract with atorvastatin daily for 3 weeks increases the maximum plasma concentration of atorvastatin by 6-fold and reduces the clearance of atorvastatin (104211).

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with CYP1A2 substrates may increase the effects of CYP1A2 substrates.  Details In vitro research shows that the methanol extract of rooibos leaves and stems inhibits CYP1A2 enzyme activity (101251).

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with CYP2C19 substrates may increase the effects of CYP2C19 substrates.  Details In vitro research shows that the methanol extract of rooibos leaves and stems strongly inhibits CYP2C19 enzyme activity (101251).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with CYP2C9 substrates may increase the effects of CYP2C9 substrates.  Details In vitro research shows that the methanol extract of rooibos leaves and stems inhibits CYP2C9 enzyme activity (101251).

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with CYP2D6 substrates may increase the effects of CYP2D6 substrates.  Details In vitro research shows that the methanol extract of rooibos leaves and stems inhibits CYP2D6 enzyme activity (101251).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking rooibos with CYP3A4 substrates may increase the effects of CYP3A4 substrates.  Details In vitro research shows that the methanol extract of rooibos leaves and stems strongly inhibits CYP3A4 enzyme activity (101251).

(Read more about ROOIBOS)

CYTOCHROME P450 2B6 (CYP2B6) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Sweet Annie may alter plasma levels and clinical effects of drugs metabolized by CYP2B6.  Details In vitro research shows that the Sweet Annie constituent artemisinin induces CYP2B6, possibly increasing CYP2B6 activity by 1.6-fold (92501,109316). However, Sweet Annie extract seems to inhibit the activity of CYP2B6 in vitro, suggesting that other constituents of Sweet Annie play a role in its effects on the overall activity of this enzyme (109316). More information is needed to determine whether taking Sweet Annie extract affects the metabolism of CYP2B6 substrates.

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Sweet Annie may alter plasma levels and clinical effects of drugs metabolized by CYP3A4.  Details In vitro research shows that the Sweet Annie constituent artemisinin induces CYP3A4, possibly increasing CYP3A4 activity by 1.9-fold (92501). However, Sweet Annie extract seems to inhibit the activity of CYP3A4 in vitro, suggesting that other constituents of Sweet Annie play a role in its effects on the overall activity of this enzyme (109316). More information is needed to determine whether taking Sweet Annie extract affects the metabolism of CYP3A4 substrates.

HEPATOTOXIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use might have additive adverse hepatotoxic effects.  Details There is some concern that Sweet Annie can adversely affect the liver (16895,103254,103255).

(Read more about SWEET ANNIE)

General ...Orally, black walnut fruit (nut) is well tolerated. However, the leaf, bark, and hull of black walnut contain high quantities of tannins, which may cause adverse effects when used orally or topically.
Most Common Adverse Effects:
Orally: The leaf, bark, and hull can cause gastrointestinal upset.
Topically: Hull preparations may cause a temporary yellow or brown discoloration at the site of application. The leaf, bark, and hull can cause skin irritation.
Serious Adverse Effects (Rare):
Orally: The bark may increase the risk for tongue cancer or lip leukoplakia when used long-term.
All routes of administration: Allergic reactions, including anaphylaxis.

Dermatologic ...Topically, black walnut leaf, bark, or hull may have an irritating effect on the skin due to tannin content. Black walnut hull preparations might cause a temporary yellow or brown discoloration of the skin at the site of application (12).

Gastrointestinal ...Orally, black walnut leaf, bark, or hull may cause gastrointestinal upset due to tannin content (12). Also, daily use of the juglone-containing bark of a related species (English walnut) is associated with increased risk of tongue cancer and lip leukoplakia (2,12).

Hepatic ...Orally, black walnut leaf, bark, or hull may cause liver damage if taken for extended periods of time due to tannin content (12).

Immunologic ...Tree nuts, which include black walnuts, can cause allergic reactions in sensitive individuals. Due to the prevalence of this allergy in the general population, tree nuts are classified as a major food allergen in the United States (105410).

Renal ...Orally, black walnut leaf, bark, or hull may cause kidney damage if taken for extended periods of time due to tannin content (12).

(Read more about BLACK WALNUT)

General ...Orally, catnip is generally well-tolerated when used in appropriate amounts.
Most Common Adverse Effects:
Orally: Headache, malaise, vomiting.

Gastrointestinal ...Orally, large amounts of catnip might cause stomachache and vomiting (6,2596).

Neurologic/CNS ...Orally, taking too much catnip may result in headache and malaise (6). In one case, a toddler developed a stomachache and irritability, followed by lethargy and a hypnotic state, after ingesting raisins soaked in catnip tea and chewing on the tea bag (5,2596).

(Read more about CATNIP)

General ...Orally, clove is well tolerated when consumed as a spice; however, clove oil in doses of only 5-10 mL can be toxic in children. Topically, clove is generally well tolerated. When inhaled or used intravenously, clove may be unsafe.
Most Common Adverse Effects:
Topically: Burning, contact dermatitis, dental decay, itching, mucous membrane irritation, tingling, ulcers.
Inhaled: Dental decay, hypertension, itching, tachycardia.
Serious Adverse Effects (Rare):
Orally: Liver failure, respiratory distress.
Inhaled: Pneumonitis, pulmonary edema, respiratory distress.

Cardiovascular ...Smoking clove cigarettes increases heart rate and systolic blood pressure (12892).

Dental ...Population research has found that the risk of dental decay is increased in clove cigarette smokers (43332). Repeated topical application of clove in the mouth can cause gingival damage and skin and mucous membrane irritation (4,272,512). Eugenol, a constituent of clove and a material commonly found in dentistry, has been associated with side effects including gum inflammation and irritation (43365,43373,43522).

Dermatologic ...The American Dental Association has accepted clove for professional use, but not nonprescription use, due to potential damage to soft tissue that may be induced by clove application. In clinical research, small aphthous-like ulcers appeared in the area of the mouth where clove gel was applied in four participants (43448). Skin irritation and stinging have been reported with clove oil application (43338,43626). In a 24-year-old, exposure to a clove oil spill resulted in permanent local anesthesia and anhidrosis, or lack of sweating, at the affected area (43626).

Endocrine ...A case of hypoglycemia and metabolic acidosis have been reported after administration of one teaspoon of clove oil to a seven-month-old infant (43457). A case of electrolyte imbalance following accidental ingestion by a seven-month-old has also been reported (6).

Hematologic ...A case of disseminated intravascular coagulation has been reported in a 2-year-old patient after consuming between 5-10 mL of clove oil. The patient was treated with heparin, fresh frozen plasma, protein C, factor VII, and antithrombin III. On the fifth day, the patient started to improve and made a full recovery (43652).

Hepatic ...There are three cases of hepatic failure occurring in children after ingestion of 5-10 mL of clove oil (43395,43419,43652). Liver injury also occurred in a 3-year-old male (96949). These patients were successfully treated with N-acetylcysteine. The course of liver injury seems to be milder and shorter with early N-acetylcysteine treatment (43395,43419,96949). Another patient, who also presented with disseminated intravascular coagulation, was successfully treated with heparin, fresh frozen plasma, protein C, factor VII, and antithrombin III (43652).

Immunologic ...Contact dermatitis and urticaria has been reported following topical exposure to clove oil or eugenol, a constituent of clove oil (12635,43339,43606,43346).

Neurologic/CNS ...CNS depression has been reported in a 7-month-old who was given one teaspoon of clove oil accidentally in place of mineral oil for diarrhea. The patient was successfully treated with supportive care and gastric lavage (43457). A case of confusion and inability to speak has been reported secondary to oral exposure to clove oil and alcohol. The patient required intubation and was successfully treated with thiamine and normal saline (43580). Seizure and coma have been reported in a two-year-old male after ingesting 5-10 mL of clove oil (43652).

Pulmonary/Respiratory ...Clove cigarettes have been associated with throat and chest tightness (43337), pulmonary edema (43618), and fatal aspiration pneumonitis (43599). The causative factor may be clove alone or clove along with other substances found in cigarettes. Clove cigarettes contain significant amounts of nicotine, tar, and carbon monoxide and increase plasma levels of nicotine and exhaled carbon monoxide, which might cause long-term health effects similar to tobacco smoking (12892). According to the American Medical Association, inhaling clove cigarette smoke has been associated with severe lung injury in a few susceptible individuals with prodromal respiratory infection. Also, some individuals with normal respiratory tracts have apparently suffered aspiration pneumonitis as the result of a diminished gag reflex induced by a local anesthetic action of eugenol, which is volatilized into the smoke (43602).
Intravenous injection of clove oil in a 32-year-old female resulted in hypoxia, acute dyspnea, interstitial and alveolar infiltrates, and non-cardiogenic pulmonary edema. The patient was managed with supplemental oxygen and recovered over the next seven days (16384).
Occupational exposure to eugenol, a constituent of clove, has also been reported to cause asthma and rhinitis (43492).

Renal ...Proteinuria and other urinary abnormalities were observed in a seven-month-old infant given one teaspoon of clove oil accidentally in place of mineral oil for diarrhea. The patient was successfully treated with supportive care and gastric lavage (43457).

(Read more about CLOVE)

General ...There is a limited amount of information available about the adverse effects of elecampane.
Most Common Adverse Effects:
Topically: Allergic contact dermatitis in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Diarrhea, vomiting, spasms, and symptoms of paralysis at high doses.

Gastrointestinal ...Orally, large doses of elecampane may cause vomiting and diarrhea (12).

Immunologic ...Topically, elecampane can cause allergic contact dermatitis (6958,48729,48731), especially in individuals sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many other herbs.

Musculoskeletal ...Orally, large doses of elecampane may cause spasms and symptoms of paralysis (12).

(Read more about ELECAMPANE)

General ...Orally and topically, fennel seems to be well tolerated.
Most Common Adverse Effects:
Orally: Gastrointestinal discomfort, photosensitivity, and allergic reactions in sensitive individuals.
Serious Adverse Effects (Rare):
Orally: Seizures.

Dermatologic ...Advise patients to avoid excessive sunlight or ultraviolet light exposure while using fennel (19). Allergic reactions affecting the skin such as atopic dermatitis and photosensitivity may occur in patients who consume fennel (6178,49507).

Gastrointestinal ...Orally, fennel may cause gastrointestinal complaints, including nausea and vomiting (19146,104196).

Hematologic ...Methemoglobinemia has been reported in four infants following intoxication related to ingestion of a homemade fennel puree that may have been made from improperly stored fennel (49444).

Immunologic ...A case report describes an 11-year-old male who developed an allergy to fennel-containing toothpaste. Immediately after using the toothpaste, the patient experienced sneezing, coughing, itchy mouth, rhinorrhea, nasal congestion, wheezing, difficulty breathing, and palpitations, which resolved within 10 minutes of spitting out the toothpaste and rinsing the mouth. In challenge tests, the patient reacted to chewing fresh fennel root, but not ground fennel seeds (103822).

Neurologic/CNS ...Orally, fennel oil has been associated with tonic clonic and generalized seizures (12868). New-onset cluster headaches are reported in a 24-year-old female while using a toothpaste containing fennel and camphor for 3 months. The headaches resolved upon stopping the toothpaste (112368). It is unclear if this adverse effect can be attributed to fennel, camphor, or the combination.

Pulmonary/Respiratory ...Orally, fennel and fennel seed have been reported to cause bronchial asthma (49478).

(Read more about FENNEL)

General ...Orally, gentian root, in combination with other herbs, seems to be generally well tolerated. There is insufficient reliable information available about the adverse effects of gentian when taken as a medicine alone.
Most Common Adverse Effects:
Orally: Allergic skin reactions, gastrointestinal discomfort.

Gastrointestinal ...Orally, gentian root, in combination with other herbs, has been reported to cause gastrointestinal adverse effects (374,379). Gastrointestinal intolerance occurred in patients with cancer-associated anorexia who took gentian tincture 1 mL three times daily, in conjunction with turmeric 1 gram and ginger 1 gram twice daily, for 14 days. Six of 17 patients discontinued the regimen due to nausea, 3 due to vomiting, 2 due to diarrhea, and 2 due to bloating. It is unclear if this gastrointestinal intolerance was caused by gentian, the other herbs, or the patients' predisposing conditions (96263).

Immunologic ...Orally, gentian root, in combination with other herbs, has been reported to cause allergic skin reactions (374,379). It is unclear if these reactions were caused by gentian, the other herbs, or the combination.

(Read more about GENTIAN)

General ...Orally, ginger is generally well tolerated. However, higher doses of 5 grams per day increase the risk of side effects and reduce tolerability. Topically, ginger seems to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal discomfort, burping, diarrhea, heartburn, and a pepper-like irritant effect in the mouth and throat. However, some of these mild symptoms may be reduced by ingesting encapsulated ginger in place of powdered ginger.
Topically: Dermatitis in sensitive individuals.

Cardiovascular ...Orally, use of ginger resulted in mild arrhythmia in one patient in a clinical trial (16306).

Dermatologic ...Orally, ginger can cause hives (17933), as well as bruising and flushing (20316) or rash (20316).
Topically, ginger can cause dermatitis in sensitive individuals (12635,46902).

Gastrointestinal ...Orally, common side effects of ginger include nausea (17933,22602,89898,101761), belching (10380,103359), dry mouth (103359), dry retching (10380), vomiting (10380), burning sensation (10380), oral numbness (22602), abdominal discomfort (5343,89898,96253), heartburn (5343,7624,12472,16306,20316,51845,89894,89895,89898,89899)(101760,101761,101762,111543), diarrhea (5343,101760), constipation (89898,101760,101761), or a transient burning or "chilly hot" sensation of the tongue and throat (52076). Orally, Number Ten, a specific product composed of rhubarb, ginger, astragalus, red sage, and turmeric, can increase the incidence of loose stools (20346).
Four cases of small bowel obstruction due to ginger bolus have been reported following the ingestion of raw ginger without sufficient mastication (chewing). In each case, the bolus was removed by enterotomy. Ginger is composed of cellulose and therefore is resistant to digestion. It can absorb water, which may cause it to swell and become lodged in narrow areas of the digestive tract (52115).

Genitourinary ...In one clinical trial, some patients reported increased menstrual bleeding while taking a specific ginger extract (Zintoma, Goldaru) 250 mg four times daily orally for 3 days (17931). An "intense" urge to urinate after 30 minutes was reported in two of eight patients given 0.5-1 gram of ginger (7624). However, this effect has not been corroborated elsewhere. Dysuria, flank pain, perineal pain, and urinary stream interruption have been reported in a 43-year-old male who drank ginger tea, containing 2-3 teaspoons of dry ginger, daily over 15 years. The adverse effects persisted for 4 years and were not associated with increases in urinary frequency or urgency. Upon discontinuing ginger, the patient's symptoms began to improve within one week and completely resolved after eight weeks, with no relapses six months later (107902).

Immunologic ...In one case report, a 59-year-old Japanese female with multiple allergic sensitivities developed pruritus and then anaphylactic shock after taking an oral ginger-containing herbal supplement for motion sickness (Keimei Gashinsan, Keimeido). The patient had used this supplement previously for over 20 years with no allergic reaction. The authors theorized the development of a cross-reactivity to ginger after the use of an oral supplement containing zedoary and turmeric, which are also in the Zingiberaceae family (102463).

Neurologic/CNS ...Orally, ginger may cause sedation, drowsiness, or dizziness (16306,17933,51845).

(Read more about GINGER)

General ...Orally, olive fruit is well tolerated when used in typical food amounts. Olive leaf extract seems to be well tolerated.
Most Common Adverse Effects:
Orally: Headache and stomach discomfort.

Dermatologic ...Orally, one patient in one clinical trial reported bad skin and acne after using olive leaf extract (101860).

Gastrointestinal ...Orally, three patients in one clinical trial reported stomach ache after using olive leaf extract (101860).

Neurologic/CNS ...Orally, three patients in one clinical trial reported headache after using olive leaf extract (101860).

Psychiatric ...In one case report, a 67-year-old female experienced irritability, anger, a lack of control, and feelings of sadness and negativity after consuming a multi-ingredient product containing olive leaf extract 5 grams, horseradish root, and eyebright daily for 38 days. All psychiatric symptoms disappeared within days of stopping the combined product. It is hypothesized that the hydroxytyrosol component of olive leaf extract contributed to these symptoms due to its chemical similarity to dopamine; however, it is not clear if these symptoms were due to the olive leaf extract or to the other ingredients (96245).

Pulmonary/Respiratory ...Olive tree pollen can cause seasonal respiratory allergy (1543).

(Read more about OLIVE)

General ...Orally, topically, or rectally, peppermint oil is generally well tolerated. Inhaled, peppermint oil seems to be well tolerated. Intranasally, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted. Orally, peppermint leaf seems to be well tolerated.
Most Common Adverse Effects:
Orally: Abdominal pain, anal burning, belching, diarrhea, dry mouth, heartburn, nausea, and vomiting.
Topically: Burning, dermatitis, irritation, and redness.

Dermatologic ...Topically, peppermint oil can cause skin irritation, burning, erythema, and contact dermatitis (3802,11781,31528,43338,68473,68457,68509,96361,96362). Also, a case of severe mucosal injury has been reported for a patient who misused an undiluted over the counter mouthwash that contained peppermint and arnica oil in 70% alcohol (19106).
In large amounts, peppermint oil may cause chemical burns when used topically or orally. A case of multiple burns in the oral cavity and pharynx, along with edema of the lips, tongue, uvula, and soft palate, has been reported for a 49-year-old female who ingested 40 drops of pure peppermint oil. Following treatment with intravenous steroids and antibiotics, the patient's symptoms resolved over the course of 2 weeks (68432). Also, a case of chemical burns on the skin and skin necrosis has been reported for a 35-year-old male who spilled undiluted peppermint oil on a previous skin graft (68572). Oral peppermint oil has also been associated with burning mouth syndrome and chronic mouth ulceration in people with contact sensitivity to peppermint (6743). Also, excessive consumption of mint candies containing peppermint oil has been linked to cases of stomatitis (13114).

Gastrointestinal ...Orally, peppermint oil can cause heartburn, nausea and vomiting, anal or perianal burning, abdominal pain, belching, dry mouth, diarrhea, and increased appetite (3803,6740,6741,6742,10075,11779,11789,17682,68497,68514)(68532,68544,96344,96360,102602,104219,107955). Enteric-coated capsules might help to reduce the incidence of heartburn (3802,4469,6740,11777). However, in one clinical study, a specific enteric-coated formulation of peppermint oil (Pepogest; Nature's Way) taken as 180 mg three times daily was associated with a higher rate of adverse effects when compared with placebo (48% versus 31%, respectively). Specifically, of the patients consuming this product, 11% experienced belching and 26% experienced heartburn, compared to 2% and 12%, respectively, in the placebo group (107955). A meta-analysis of eight small clinical studies in patients with irritable bowel syndrome shows that taking enteric-coated formulations of peppermint oil increases the risk of gastroesophageal reflux symptoms by 67% when compared with a control group (109980). Enteric-coated capsules can also cause anal burning in people with reduced bowel transit time (11782,11789).

Genitourinary ...Orally, a sensitive urethra has been reported rarely (102602).

Hepatic ...One case of hepatocellular liver injury has been reported following the oral use of peppermint. Symptoms included elevated liver enzymes, fatigue, jaundice, dark urine, and signs of hypersensitivity. Details on the dosage and type of peppermint consumed were unavailable (96358).

Immunologic ...One case of IgE-mediated anaphylaxis, characterized by sudden onset of lip and tongue swelling, tightness of throat, and shortness of breath, has been reported in a 69-year-old male who consumed peppermint candy (89479). An allergic reaction after use of peppermint oil in combination with caraway oil has been reported in a patient with a history of bronchial asthma (96344). It is not clear if this reaction occurred in response to the peppermint or caraway components.

Neurologic/CNS ...Orally, headache has been reported rarely (102602).

Ocular/Otic ...Orally, peppermint has been reported to cause blurry vision (3803).

(Read more about PEPPERMINT)

General ...Orally, quassia can cause mucous membrane irritation, nausea, and vomiting when used in medicinal amounts (4,18). Long-term use can cause vision changes and blindness (18).
Topically, quassia seems to be well tolerated (99995). No adverse effects have been reported.

Gastrointestinal ...Orally, quassia has been reported to cause mucous membrane irritation, nausea, and vomiting when used in medicinal amounts (4,18).

Ocular/Otic ...Orally, long-term use of quassia can cause vision changes and blindness (18).

(Read more about QUASSIA)

General ...There is currently a limited amount of information on the adverse effects of roobios. A thorough evaluation of safety outcomes has not been conducted.
Serious Adverse Effects (Rare):
Orally: Hepatotoxicity.

Hepatic ...Orally, large and long-term doses of rooibos tea might cause hepatotoxicity in some susceptible patients. In a case-report, a 37-year-old man drinking 10 cups of rooibos tea daily for over a year presented with hepatic dysfunction and thrombocytopenia (101254).

(Read more about ROOIBOS)

General ...Orally, Sweet Annie is generally well-tolerated.
Most Common Adverse Effects:
Orally: Nausea and vomiting.
Serious Adverse Effects (Rare):
Orally: Hepatotoxicity.

Gastrointestinal ...Orally, Sweet Annie might cause gastrointestinal upset including nausea and vomiting in some patients (11058,112393).

Hepatic ...Orally, Sweet Annie might cause hepatic adverse effects (16895,103254,103255). In one case, a 52-year-old patient developed hepatitis after taking the Sweet Annie constituent artemisinin 200 mg three times daily for 10 days. The patient developed abdominal pain and dark urine and was found to have elevated liver enzymes consistent with hepatitis. Symptoms resolved within 2 weeks of discontinuing use. Although it is possible this supplement caused liver disease in this patient, it is not certain. In clinical trials evaluating artemisinin, elevated liver enzymes have only been reported in around 0.9% of patients. However, the dose of artemisinin in this case was substantially higher than a typical dose (16895). A case of severe acute cholestatic hepatitis has also been reported in a 51-year-old male who drank Sweet Annie tea daily, prepared using 1.25 grams of Sweet Annie powder, for malaria prophylaxis during a 4-week trip to Ethiopia. Three weeks after his return, he presented with malaise, abdominal discomfort, jaundice, elevated liver enzymes, and markers of cholestasis. The patient was treated with corticosteroids and ursodeoxycholic acid and ultimately recovered (103255).
A series of cases linking the use of a supercritical carbon dioxide extract of Sweet Annie to hepatoxicity has also been reported. Of the 29 reports of adverse hepatic reactions to this extract, 19 patients noted symptoms within 12 weeks of starting the extract, 16 patients experienced jaundice, and 9 patients required hospitalization. Other common symptoms of hepatotoxicity included abdominal pain, vomiting, nausea, fever, headache, anorexia, malaise, fatigue, and lethargy. All but one case involved doses below or up to the extract's recommended dose of 300 mg daily. Upon discontinuation, symptoms resolved completely or were improved in nearly all cases (103254).

Immunologic ...One case of a mild allergic reaction to Sweet Annie tea has been reported. The reaction was characterized by a rash and cough that resolved quickly and did not require treatment (11059). When low doses are taken sublingually by individuals allergic to Sweet Annie, numbness of the tongue and throat itching have been reported (109315,112392,112393,112394).

(Read more about SWEET ANNIE)