Urinary Tract Maintenance Complex Tea by TerraVita

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Benign prostatic hyperplasia (BPH). Oral goldenrod has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in adults with BPH, some of whom were already receiving treatment for their symptoms, shows that taking 1200 mg of a specific product containing water-soluble extracts of goldenrod, boldo, chanca piedra, fireweed, and spiny restharrow (Fluxonorm, Omega Pharma) for 30 days improves lower urinary tract symptom scores by about 50% when compared to baseline. Maximum urinary flow rate and quality of life were also improved when compared with baseline (106432). The validity of these findings is limited by the lack of a comparator group.
• Dental plaque. Topical goldenrod has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in healthy adults shows that using a specific toothpaste (Bucovia, Givaudan) containing goldenrod extract 0.3% and sodium fluoride 0.15% twice daily for 4 weeks improves plaque index scores when compared to baseline. These effects were not different from use of a toothpaste containing only sodium fluoride 0.15%, although the study may have been inadequately powered to detect a difference between groups. Also, it is unclear if these effects are due to goldenrod, sodium fluoride, or the combination (105115).
• Kidney stones (nephrolithiasis). Although there has been interest in using oral goldenrod for kidney stones, there is insufficient reliable information about the clinical effects of goldenrod for this purpose.
• Urinary tract infections (UTIs). Oral goldenrod has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A secondary analysis of clinical research in females with a UTI who were not taking antibiotics shows that taking a specific combination supplement (Aqualibra, Medice Arzneimittel Pütter GmbH & Co. KG) containing extracts of goldenrod 360 mg, Java tea 180 mg, and spiny restharrow root 160 mg three times daily for 7 days modestly improves clinical symptom scores when compared with placebo. Individuals taking the combination supplement also had a 63% reduction in microbial count, compared with 25% in those taking placebo. Additionally, antibiotics were prescribed in only 15% of those taking the combination product, compared with 49% of those taking placebo (102763). It is unclear if these findings are due to goldenrod, other ingredients, or the combination. More evidence is needed to rate goldenrod for these uses.

(Read more about GOLDENROD)

There is insufficient reliable information available about the effectiveness of hyssop.

(Read more about HYSSOP)

LIKELY EFFECTIVE

• Constipation. Taking senna orally is effective for the short-term treatment of constipation. Details: Senna is an FDA-approved nonprescription drug marketed for the short-term treatment of constipation in adults and children ages 2 years and older (15429,15433,15436,15441,15442,74545,74607,74609,74613,74615). Senna usually produces a laxative effect 6-10 hours after oral administration (15429,96559). However, in children ages 3-15 years, mineral oil and lactulose might be more effective (15434,15435). Taking senna with psyllium is also effective for the short-term treatment of constipation (8424,74593), with the combination increasing stool moisture to a greater degree than psyllium alone (8424). In patients with opioid or loperamide-induced constipation, taking senna appears to be as effective as lactulose, psyllium, and docusate for relieving constipation (15432,74586,74644,74650). Some population research has found that senna may be more effective than docusate, polyethylene glycol, and lactulose for preventing problematic constipation, the need for an enema, and abdominal imaging in pediatric cancer patients receiving opioids (92710). Senna also seems to be beneficial in chronic constipation. Clinical guidelines published by the American Gastroenterology Association and American College of Gastroenterology in 2023 give a conditional recommendation suggesting the use of senna over managing chronic idiopathic constipation without senna based on low-quality of evidence conducted over 4 weeks (112859). In geriatric patients, senna plus psyllium is more effective than lactulose for treating chronic constipation (15438,15439,15440). Also, a small study in middle-aged adults with chronic idiopathic constipation shows that taking senna (ALOSENN granules) 500 mg twice daily for 4 weeks seems to be similarly effective to taking magnesium oxide 500 mg three times daily (105959).

POSSIBLY EFFECTIVE

• Bowel preparation. Taking oral senna might be effective for bowel cleansing before colonoscopy. Details: A meta-analysis of 10 clinical trials in adults shows that taking senna alone or with other bowel preparations does not improve bowel cleansing before elective colonoscopy when compared with non-senna bowel preparations. However, in a subgroup analysis of 3 clinical studies, taking senna solution alone is about 2.5 times more likely to result in a clean bowel when compared with polyethylene glycol alone (112893). The interpretation of these findings is limited by varied senna dosages and regimens. Additionally, 2 clinical studies that were not included in this meta-analysis show that senna is as effective or more effective than polyethylene glycol for improving bowel cleanse quality (15431,40088). Conversely, other studies show that polyethylene glycol is superior to senna (40086,74587,74606,74636). It is also unclear if taking senna with polyethylene glycol improves bowel cleansing when compared with polyethylene glycol alone (74583,74585). Some clinical studies show that senna is as effective as castor oil and bisacodyl for bowel cleansing (74548,74603,74624). Although taking senna alone is less effective than sodium phosphate (15431,74567,74570,74653,92712), some evidence suggests that taking a combination of senna, sodium picosulfate, and polyethylene glycol is more effective than sodium phosphate for bowel cleansing prior to colonoscopy (74538). Limited research has also assessed the benefit of adding senna to a preparation regimen for small bowel capsule endoscopy; however, it is unclear whether the addition of senna improves endoscopy outcomes when compared with the preparation regimen alone (96557). There is insufficient reliable information available about the effectiveness of senna for its other uses.

(Read more about SENNA)

POSSIBLY INEFFECTIVE

• Urinary tract infections (UTIs). Clinical research does not support the use of oral uva ursi for treatment of UTIs. For prevention of UTIs, oral uva ursi has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A large clinical study in females with uncomplicated UTI shows that taking uva ursi tablets providing 210 mg arbutin orally three times daily for 5 days is less effective than a single dose of fosfomycin 3 grams for reducing UTI symptom burden and the number of rescue antibiotic courses. Rescue antibiotics were needed in 44% of patients receiving uva ursi, compared with 23% of those receiving fosfomycin. On day 4, the percentage of patients with symptom resolution was 49% with uva ursi, compared to 65% with fosfomycin. Pyelonephritis occurred in 8 patients on uva ursi and 2 patients on fosfomycin (109535). Also, a large clinical study in females experiencing symptoms of a UTI shows that taking uva ursi extract 1200 mg three times daily for 3-5 days does not improve symptoms or reduce the need for antibiotics when compared with placebo (101815). Uva ursi has also been evaluated for the prevention of UTIs. One small clinical study in females with recurrent UTI shows that taking a specific combination product containing uva ursi and dandelion (UVA-E, Medic Herb AB) 3 tablets three times daily for one month reduces the recurrence rate of UTIs when compared with placebo (1932). It is not clear if this effect is due to uva ursi, dandelion, or the combination.

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Benign prostatic hyperplasia (BPH). Although there is interest in using oral uva ursi for BPH, there is insufficient reliable information about the clinical effects of uva ursi for this condition.
• Bronchitis. Although there is interest in using oral uva ursi for bronchitis, there is insufficient reliable information about the clinical effects of uva ursi for this condition. More evidence is needed to rate uva ursi for these uses.

(Read more about UVA URSI)

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Arrhythmia. Although there has been interest in using oral yerba mate for arrhythmia, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Athletic performance. It is unclear if oral yerba mate is beneficial for improving athletic performance. Details: A small clinical study shows that taking yerba mate 5 grams orally daily for 5 days prior to a cycling exercise shortens time to completion by 2% and modestly improves absolute power when compared with placebo in trained athletes (96471).
• Cognitive function. It is unclear if oral yerba mate is beneficial for improving cognitive function. Details: Preliminary clinical research shows that drinking a single beverage containing one tablespoon of yerba mate does not improve vigilance, working memory, reaction time, or accuracy when compared with decaffeinated coffee controls in healthy females ages 17-35 years (86712).
• Chronic fatigue syndrome (CFS). Although there has been interest in using oral yerba mate for CFS, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Depression. Although there has been interest in using oral yerba mate for depression, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Diabetes. It is unclear if oral yerba mate is beneficial in patients with diabetes. Details: Preliminary clinical research shows that drinking yerba mate tea, prepared by steeping 6.6 grams of leaves for 10 minutes in 330 mL of boiling water, three times daily for 60 days decreases fasting blood glucose by up to 17% and glycated hemoglobin (HbA1c) by 0.85% when compared with baseline in patients with type 2 diabetes (86693). The validity of these findings is limited by the lack of a comparator group.
• Dyslipidemia. It is unclear if oral yerba mate is beneficial in patients with dyslipidemia. Details: A meta-analysis of 7 small, mostly low to moderate quality clinical studies in adults shows that taking yerba mate orally does not reduce levels of total, low-density lipoprotein (LDL) cholesterol, or triglycerides or improve high-density lipoprotein (HDL) cholesterol when compared with placebo or dietary intervention (111738). However, the validity of this study is limited by the heterogeneity of the included studies which enrolled patients with varying conditions and used various forms and doses of yerba mate. Other clinical research in patients with dyslipidemia or hypercholesterolemia shows that drinking 330 mL of tea containing yerba mate 20 mg/mL three times daily for 40 days reduces LDL cholesterol levels by 9% and increases HDL cholesterol levels by 4% when compared with baseline. The effects of yerba mate were similar between patients on low- to moderate-intensity statin therapy and those not taking statins. Drinking yerba mate tea did not affect triglyceride levels (86657).
• Fatigue. Although there has been interest in using oral yerba mate for fatigue, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Headache. Although there has been interest in using oral yerba mate for headache, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Heart failure. Although there has been interest in using oral yerba mate for heart failure, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Impaired glucose tolerance (Prediabetes). It is unclear if oral yerba mate is beneficial in patients with prediabetes. Details: Clinical research shows that drinking yerba mate tea, prepared by steeping 6.6 grams of leaves for 10 minutes in 330 mL of boiling water, three times daily for 60 days reduces glycated hemoglobin (HbA1C) by 0.4%, but not fasting blood glucose levels, when compared with baseline in patients with prediabetes (86693). The validity of these findings is limited by the lack of a comparator group.
• Joint pain. Although there has been interest in using oral yerba mate for joint pain, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Kidney stones (nephrolithiasis). Although there has been interest in using oral yerba mate for nephrolithiasis, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Mental alertness. Although there has been interest in using oral yerba mate for mental alertness, there is insufficient reliable information about the clinical effects of yerba mate for this purpose.
• Muscle strength. It is unclear if oral yerba mate improves muscle strength. Details: A small clinical crossover study in males shows that consuming a beverage containing 3 grams of yerba mate (Matte Leão, Valinhos Brazil) 1-hour prior to bench press and leg press strength training does not improve muscle strength when compared with placebo (111739).
• Obesity. It is unclear if oral yerba mate is beneficial in patients with obesity. Details: Although some observational research in healthy patients has found that high consumption of yerba mate is associated with increased weight (99322), most preliminary clinical research in adults with obesity shows that consuming yerba mate might improve some parameters (11866,92152,96470). Two, small, randomized controlled trials in obese Korean adults shows that taking yerba mate 3 grams daily, in 2-3 divided doses, for 6-12 weeks does not reduce weight, body mass index, or lipid levels when compared with placebo. Taking yerba mate modestly improved other measures, such as fat mass, waist-hip ratio, and waist circumference when compared with baseline, but these results were not consistent between trials and the studies may have been inadequately powered to detect a difference between groups (92152,96470).
• Osteoporosis. It is unclear if oral yerba mate is beneficial in patients with osteoporosis. Details: In an observational study, consumption of at least 1 liter of yerba mate tea daily for a minimum of 4 years was associated with higher lumbar spine and femoral neck bone densities, with increases of 9.7% and 6.2%, respectively (17184). In contrast, a small case-control study found no association between yerba mate consumption and markers of bone resorption and formation in postmenopausal adults, regardless of the duration of yerba mate consumption (96468). Neither study identified an association between fracture rates; however, these studies may have been inadequately powered to detect a difference between groups (17184,96468).
• Parkinson Disease. It is unclear if oral yerba mate is beneficial in preventing Parkinson disease. Details: A small observational study has found that high consumption of yerba mate tea is associated with 59% to 63% lower odds of being diagnosed with Parkinson disease when compared with no consumption of yerba mate (106860).
• Urinary tract infections (UTIs). Although there has been interest in using oral yerba mate for UTIs, there is insufficient reliable information about the clinical effects of yerba mate for this purpose. More evidence is needed to rate yerba mate for these uses.

(Read more about YERBA MATE)

POSSIBLY SAFE ...when used topically as a toothpaste, short-term. A specific toothpaste (Bucovia, Givaudan) containing goldenrod extract 0.3% and sodium fluoride 0.15% has been used safely twice daily for up to 4 weeks (105115). There is insufficient reliable information available about the safety of goldenrod when used orally or when applied topically to the skin.

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

(Read more about GOLDENROD)

LIKELY SAFE ...when used orally in amounts commonly found in foods. Hyssop, hyssop oil, and hyssop extract have Generally Recognized as Safe (GRAS) status in the US (4912). There is insufficient reliable information available about the safety of hyssop when used in medicinal amounts.

PREGNANCY: LIKELY UNSAFE
when used orally because it might cause uterine stimulant and menstrual stimulant effects (12).

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about HYSSOP)

LIKELY SAFE ...when used orally and appropriately, short-term. Senna is an FDA-approved nonprescription drug (8424,15429,15431,15442,40086,40088,74535,74545,74548,74562)(74567,74570,74583,74585,74586,74587,74593,74603,74606,74607)(74609,74613,74615,74624,74636,74639,74644,74650,74653,92711)(92712).

POSSIBLY UNSAFE ...when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095).

CHILDREN: LIKELY SAFE
when used orally and appropriately, short-term. Senna is an FDA-approved nonprescription drug for use in children 2 years and older. (15429,15434,15435).

CHILDREN: POSSIBLY UNSAFE
when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095,105956).

PREGNANCY: POSSIBLY SAFE
when used orally and appropriately, short-term (15429,24480). POSSIBLY UNSAFE...when used orally long-term or in high doses. Long-term, frequent use, or use of high doses has been linked to serious side effects including laxative dependence and liver toxicity (13057,13095).

LACTATION: POSSIBLY SAFE
when used orally and appropriately, short term. Although small amounts of constituents of senna cross into breast milk, senna has been taken while breast-feeding with apparent safety. Senna does not cause changes in the frequency or consistency of infants' stools. (6026,15429,15436,15437,24482,24484,24485,24486,24487,74545).

(Read more about SENNA)

POSSIBLY SAFE ...when used orally and appropriately, short-term. Uva ursi has been used with apparent safety in doses of up to 3600 mg daily for 3-5 days (101815).

POSSIBLY UNSAFE ...when used orally long-term or in high doses. There is concern about the safety of long-term or high-dose use because of the hydroquinone content of uva ursi. Hydroquinone is thought to have mutagenic and carcinogenic effects (7). At high doses (around 20 grams of dried herb) it can cause convulsions, cyanosis, delirium, shortness of breath, and collapse. At very high doses (30 grams of dried herb or more) it can be fatal (4).

CHILDREN: POSSIBLY UNSAFE
when used orally by children. Uva ursi contains hydroquinone and high tannin levels, which can cause severe liver problems in children (4,18); avoid using.

PREGNANCY: LIKELY UNSAFE
when used orally. Uva ursi can have oxytocic effects, increasing the speed of labor (4,7,19); avoid using.

LACTATION:
Insufficient reliable information available; avoid using.

(Read more about UVA URSI)

POSSIBLY SAFE ...when used orally and appropriately, short-term (11866). Yerba mate has been safely used in doses of 3 grams daily for up to 12 weeks (92152,96469,96470).

POSSIBLY UNSAFE ...when yerba mate is used orally in large amounts or for prolonged periods of time. Drinking approximately 1-2 liters, or 4-8 cups, of yerba mate daily is associated with an increased risk of cancer, including esophageal, stomach, kidney, bladder, cervical, prostate, lung, renal cell, and possibly laryngeal and mouth cancer (1528,1529,1530,1531,11863,11864,92150). Yerba mate also contains caffeine. Acute use of high doses of caffeine (more than 400 mg per day), which is found in more than 8-10 cups of yerba mate, has been associated with significant adverse effects such as tachyarrhythmia and sleep disturbances (11832). Drinking yerba mate in amounts greater than 12-15 cups daily (about 600 mg caffeine) short-term or long-term can also cause caffeinism with symptoms of anxiety possibly progressing to delirium and agitation. Chronic use of caffeine, especially in large amounts, can sometimes produce tolerance, habituation, and psychological dependence (3719). Abrupt discontinuance of caffeine can cause physical withdrawal symptoms (11733). Keep in mind that only the amount of ADDED caffeine must be stated on product labels. The amount of caffeine found in ingredients such as yerba mate, which naturally contains caffeine, does not need to be provided. This can make it difficult to determine the total amount of caffeine in a given product.

CHILDREN: POSSIBLY UNSAFE
when used orally. Yerba mate is associated with an increased risk of cancer, including esophageal, kidney, bladder, cervical, prostate, lung, and possibly mouth and laryngeal cancer (1528,1529,1530,1531,11863,11864,92150).

PREGNANCY: POSSIBLY UNSAFE
when used orally. Yerba mate is associated with an increased risk of cancer, including esophageal, kidney, bladder, cervical, prostate, lung, renal cell, and possibly mouth and laryngeal cancer (1528,1529,1530,1531,11863,11864,92150,86595,86614,86700,86701). However, teratogenic studies have not been performed. Yerba mate also contains caffeine. Caffeine crosses the placenta, producing fetal blood concentrations similar to parental levels. According to a review by Health Canada, and a subsequent large meta-analysis conducted in the US, most healthy pregnant patients can safely consume caffeine in doses up to 300 mg daily without an increased risk of spontaneous abortion, stillbirth, preterm birth, fetal growth retardation, or congenital malformations (11733,98806). It is generally recommended to avoid consuming more than 300 mg of caffeine daily, or around 6-7 cups of yerba mate daily, when pregnant (2708). High doses of caffeine throughout pregnancy have resulted in symptoms of caffeine withdrawal in newborn infants (9891,86618). Caffeine in doses of greater than 300 mg daily has also been associated with spontaneous abortion, premature delivery, and low birth weight (2709,2711), although one retrospective study found that consuming yerba mate tea during pregnancy was not associated with preterm or small for gestational age births (13113). However, this study did not consider the amount of yerba mate or caffeine consumed, only the frequency of consumption. Some research has found that intrauterine exposure to even modest amounts of caffeine, based on maternal blood levels during the first trimester, is associated with a shorter stature in children ages 4-8 years (109846).

LACTATION: POSSIBLY UNSAFE
when used orally. Yerba mate is associated with an increased risk of cancer, including esophageal, kidney, bladder, cervical, prostate, lung, renal cell, and possibly mouth and laryngeal cancer (1528,1529,1530,1531,11863,11864,92150). Whether carcinogenic constituents of yerba mate are transferred via breast milk is unknown. Yerba mate contains caffeine. Consumption of yerba mate might cause irritability and increased bowel activity in nursing infants (6026).

(Read more about YERBA MATE)

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, goldenrod might increase the effects and adverse effects of diuretic drugs.  Details In vitro and animal research suggests that goldenrod has diuretic effects (512,52565,52570,52571,52572).

(Read more about GOLDENROD)

(Read more about HYSSOP)

DIGOXIN (Lanoxin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk of adverse effects when taken with digoxin.  Details Overuse/abuse of senna increases the risk of adverse effects from cardiac glycosides, such as digoxin, due to potassium depletion (15425).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk of hypokalemia when taken with diuretic drugs.  Details Overuse of senna might compound diuretic-induced potassium loss and increase the risk for hypokalemia (15425).

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, taking senna may interfere with the absorption of exogenous estrogens.  Details Some preliminary clinical evidence suggests that senna reduces the absorption of estradiol and decreases serum concentrations of estrone and estrone sulfate by decreasing intestinal transit time (74647,74651).

STIMULANT LAXATIVES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, senna might increase the risk for fluid and electrolyte loss when taken with other stimulant laxatives.  Details Senna is a stimulant laxative; concomitant use with other stimulant laxatives might compound fluid and electrolyte loss (19,15425).

WARFARIN (Coumadin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, excessive use of senna might increase the effects of warfarin.  Details Senna has stimulant laxative effects and can cause diarrhea. Diarrhea can increase the effects of warfarin, increase international normalized ratio (INR), and increase the risk of bleeding. In one case report, excessive use of senna for 3 weeks resulted in diarrhea, bloody stools, and an elevated INR of 11.9 (16530).

(Read more about SENNA)

CYTOCHROME P450 2C19 (CYP2C19) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, uva ursi may decrease the metabolism of CYP2C19 substrates.  Details In vitro, uva ursi appears to inhibit cytochrome CYP2C19 (98550). This effect 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 Theoretically, uva ursi may decrease the metabolism of CYP3A4 substrates.  Details In vitro, uva ursi appears to inhibit CYP3A4 (98550). This effect has not been reported in humans.

GLUCURONIDATED DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, uva ursi may increase levels of drugs metabolized by glucuronidation.  Details In vitro, uva ursi extract appears to strongly inhibit UDP-glucuronosyltransferase (UGT) 1A1 (UGT1A1). However, uva ursi extract does not appear to inhibit UGT1A1 in animal models (98549). This effect has not been reported in humans.

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, uva ursi may increase lithium levels, necessitating a decrease in dose.  Details Uva ursi may have diuretic properties (81637). Diuretics may increase lithium reabsorption with sodium in the proximal tubule of the kidney. Theoretically, uva ursi might reduce excretion and increase levels of lithium.

P-GLYCOPROTEIN SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, uva ursi may alter the levels of drugs transported by P-glycoprotein.  Details In vitro, uva ursi appears to inhibit the multi-drug transporter protein, P-glycoprotein (98550). This effect has not been reported in humans.

URINARY ACIDIFYING AGENTS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Effects of uva ursi in the urinary tract may be reduced by urinary acidifying agents.  Details Uva ursi seems to work best in alkaline urine. Theoretically, taking uva ursi with medications known to acidify the urine may decrease any effects of uva ursi on the urinary tract (19).

(Read more about UVA URSI)

ADENOSINE (Adenocard) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.  Details Yerba mate contains caffeine. Some evidence shows that caffeine is a competitive inhibitor of adenosine and can reduce the vasodilatory effects of adenosine in humans (38172). However, other research shows that caffeine does not seem to affect supplemental adenosine because high interstitial levels of adenosine overcome the antagonistic effects of caffeine (11771). Still, some researchers recommend that methylxanthines, such as caffeine, as well as methylxanthine-containing products, should be stopped 24 hours prior to pharmacological stress tests (11770). However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).

ALCOHOL (Ethanol) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of alcohol and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Alcohol reduces caffeine metabolism. Concomitant use of alcohol can increase caffeine serum concentrations and the risk of caffeine adverse effects (6370,24693).

ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.  Details Yerba mate contains caffeine. Caffeine is reported to have antiplatelet activity. Theoretically, it might increase the risk of bleeding when used concomitantly with these agents (8028,8029); however, this interaction has not been reported in humans.

ANTIDIABETES DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = B Theoretically, taking yerba mate with antidiabetes drugs might interfere with blood glucose control.  Details Yerba mate contains caffeine. Reports claim that caffeine might increase or decrease blood sugar (6024,8646).

BENZODIAZEPINES Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, the caffeine in yerba mate might reduce the efficacy of benzodiazepines.  Details Yerba mate contains caffeine. Caffeine can antagonize the anxiolytic effects of benzodiazepines (24951,24952,24953,24954,24955).

BETA-ADRENERGIC AGONISTS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the cardiac inotropic effects of beta-agonists, especially if taken in large amounts.  Details Yerba mate contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists (15).

CARBAMAZEPINE (Tegretol) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Theoretically, the caffeine in yerba mate might reduce the effects of carbamazepine and increase the risk for convulsions.  Details Yerba mate contains caffeine. Animal research suggests that caffeine can lower the anticonvulsant effects of carbamazepine and can induce seizures when taken in doses above 400 mg/kg (23561). Human research has shown that taking caffeine 300 mg in three divided doses along with carbamazepine 200 mg reduces the bioavailability of carbamazepine by 32% and prolongs the plasma half-life of carbamazepine two-fold in healthy individuals (23562).

CIMETIDINE (Tagamet) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Likely •  Level of Evidence = B Theoretically, cimetidine might increase the levels and adverse effects of the caffeine contained in yerba mate.  Details Yerba mate contains caffeine. Cimetidine decreases caffeine clearance by 31% to 42% (11736,24700).

CLOZAPINE (Clozaril) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.  Details Yerba mate contains caffeine. Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism (5051). Clozapine is metabolized by cytochrome P450 1A2 (CYP1A2). Although researchers speculate that caffeine might inhibit CYP1A2, there is no reliable evidence that caffeine affects CYP1A2. There is also speculation that genetic factors might make some patients more sensitive to an interaction between clozapine and caffeine (13741).

CONTRACEPTIVE DRUGS Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, contraceptive drugs might increase the levels and adverse effects of the caffeine contained in yerba mate.  Details Yerba mate contains caffeine. Contraceptive drugs decrease the rate of caffeine clearance by 40% to 65% (2714,11737).

CYTOCHROME P450 1A2 (CYP1A2) INHIBITORS Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of CYP1A2 inhibitors and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Caffeine is metabolized by CYP1A2. Theoretically, drugs that inhibit CYP1A2 may decrease the rate of caffeine clearance and increase caffeine levels (5051,11741).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, yerba mate might increase the levels and clinical effects of CYP3A4 substrates.  Details In vitro research shows that yerba mate extract inhibits CYP3A4 enzymes (105811). Theoretically, taking yerba mate may increase levels and adverse effects of CYP3A4 substrates.

DIPYRIDAMOLE (Persantine) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.  Details Yerba mate contains caffeine. Caffeine inhibits dipyridamole-induced vasodilation (11770,11772). Still, some researchers recommend that methylxanthines, such as caffeine, as well as methylxanthine-containing products, should be stopped 24 hours prior to pharmacological stress (11770). Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing (11771).

DISULFIRAM (Antabuse) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, disulfiram might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Disulfiram decreases the rate of caffeine clearance (15,11840).

DIURETIC DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the risk of hypokalemia when used concomitantly with other diuretics.  Details Yerba mate contains caffeine. Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump (23579,37905,37953,38003,38034). Diuretics can also cause lower potassium levels.

EPHEDRINE Interaction Rating = Major Do not take this combination. Severity = High •  Occurrence = Probable •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the risk for stimulant adverse effects when used concomitantly with ephedrine.  Details Use of ephedrine with caffeine can increase the risk of stimulatory adverse effects. There is evidence that using ephedrine with caffeine might increase the risk of serious life-threatening or debilitating adverse effects such as hypertension, myocardial infarction, stroke, seizures, and death (1275,6486,10307).

ESTROGENS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, estrogens might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Estrogen inhibits caffeine metabolism (2714).

ETHOSUXIMIDE (Zarontin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might reduce the effects of ethosuximide and increase the risk for convulsion.  Details Yerba mate contains caffeine. Animal research shows that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide (23560). However, this effect has not been reported in humans.

FELBAMATE (Felbatol) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might reduce the effects of felbamate and increase the risk for convulsion.  Details Yerba mate contains caffeine. Animal research shows that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate (23563). However, this effect has not been reported in humans.

FLUCONAZOLE (Diflucan) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, fluconazole might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Fluconazole decreases caffeine clearance by approximately 25% (11022,24978).

FLUTAMIDE (Eulexin) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of flutamide.  Details Yerba mate contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide (23553). However, this effect has not been reported in humans.

FLUVOXAMINE (Luvox) Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, fluvoxamine might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Fluvoxamine reduces caffeine metabolism (6370,38287).

LITHIUM Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, abrupt withdrawal of the caffeine in yerba mate might increase serum lithium levels.  Details Yerba mate contains caffeine, which has diuretic activity. When abruptly discontinued, it might alter the clearance of lithium (609). There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal (609,610).

METFORMIN (Glucophage) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, metformin might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Animal research suggests that metformin can reduce caffeine metabolism (23571). However, this effect has not been reported in humans.

METHOXSALEN (Oxsoralen) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, methoxsalen might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Methoxsalen reduces caffeine metabolism (23572).

MEXILETINE (Mexitil) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, mexiletine might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Mexiletine decreases caffeine elimination by approximately 50% (1260,11741,24981).

MIDAZOLAM (Versed) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, use of yerba mate with midazolam might increase midazolam metabolite levels and adverse effects.  Details In vitro research shows that yerba mate extract containing 6.75% chlorogenic acid significantly inhibits the metabolism of midazolam via inhibition of cytochrome P450 3A4 (CYP3A4)(105811).

MONOAMINE OXIDASE INHIBITORS (MAOIs) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase risk of a hypertensive crisis when used concomitantly with MAOIs.  Details Yerba mate contains caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies (37724,37877,37912,38108). Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis (15). In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension (91086). Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

NICOTINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase risk of hypertension when used concomitantly with nicotine.  Details Yerba mate contains caffeine. Concomitant use of caffeine and nicotine has been shown to have additive cardiovascular effects, including increased heart rate and blood pressure. Blood pressure was increased by 10.8/12.4 mmHg when the agents were used concomitantly (2719,36549).

PENTOBARBITAL (Nembutal) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, the caffeine in yerba mate might decrease the effects of pentobarbital.  Details The caffeine in yerba mate might negate the hypnotic effects of pentobarbital (13742).

PHENOBARBITAL (Luminal) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might reduce the effects of phenobarbital and increase the risk for convulsions.  Details Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital (23558,23561). However, the exact mechanism of this interaction is unclear.

PHENYLPROPANOLAMINE Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, phenylpropanolamine might increase the risk of hypertension as well as the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure (11738). Phenylpropanolamine also seems to increase caffeine serum levels (13743).

PHENYTOIN (Dilantin) Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = B Theoretically, the caffeine in yerba mate might reduce the effects of phenytoin and increase the risk for convulsions.  Details Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin (23561). The effect does not seem to be related to the seizure threshold-lowering effects of caffeine. However, the exact mechanism of this interaction is unclear.

PIOGLITAZONE (Actos) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the levels and clinical effects of pioglitazone.  Details Yerba mate contains caffeine. Animal research suggests that caffeine can modestly increase the maximum concentration, area under the curve, and half-life of pioglitazone, and also reduce its clearance. This increased the antidiabetic effects of pioglitazone (108812). However, the exact mechanism of this interaction is unclear.

QUINOLONE ANTIBIOTICS Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = B Theoretically, quinolone antibiotics might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Quinolones (also called fluoroquinolones) can decrease caffeine clearance by inhibiting cytochrome P450 1A2 (CYP1A2) enzyme (606,607,608,23554,23555,23556).

RILUZOLE (Rilutek) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, concomitant use of riluzole and yerba mate might increase levels and adverse effects of both riluzole and the caffeine in yerba mate.  Details Yerba mate contains caffeine. Caffeine and riluzole are both metabolized by cytochrome P450 1A2 (CYP1A2), and concomitant use might reduce the metabolism of one or both agents (11739).

STIMULANT DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = C Theoretically, concomitant use of stimulant drugs and yerba mate might increase stimulant adverse effects.  Details Yerba mate contains caffeine. Due to the CNS stimulant effects of the caffeine, concomitant use can increase the risk of adverse effects (11832).

TERBINAFINE (Lamisil) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = B Theoretically, terbinafine might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Terbinafine decreases the rate of caffeine clearance by 19% (11740).

THEOPHYLLINE Interaction Rating = Moderate Be cautious with this combination. Severity = Mild •  Occurrence = Probable •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of theophylline.  Details Yerba mate contains caffeine. Caffeine decreases theophylline clearance by 23% to 29% (11741).

TIAGABINE (Gabitril) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of tiagabine.  Details Yerba mate contains caffeine. Animal research suggests that chronic caffeine administration can increase the serum concentrations of tiagabine. However, concomitant use does not seem to reduce the antiepileptic effects of tiagabine (23561).

TICLOPIDINE (Ticlid) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D Theoretically, ticlopidine might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. In vitro research shows that ticlopidine can inhibit caffeine metabolism (23557). However, this effect has not been reported in humans.

VALPROATE Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, the caffeine in yerba mate might reduce the effects of valproate and increase the risk for convulsions.  Details Yerba mate contains caffeine. Animal research shows that caffeine can decrease the anticonvulsant activity of valproate (23558,23561). However, the exact mechanism of this interaction is unclear.

VERAPAMIL (Calan, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, verapamil might increase the levels and adverse effects of the caffeine in yerba mate.  Details Yerba mate contains caffeine. Verapamil increases plasma caffeine concentrations by 25% (11741).

(Read more about YERBA MATE)

General ...There is a limited amount of information available about the adverse effects of goldenrod.
Most Common Adverse Effects:
Topically: Allergic contact dermatitis in sensitive individuals.

Dermatologic ...Topically, goldenrod has been reported to cause allergic contact dermatitis (52558,52581).

Immunologic ...Topically, goldenrod has been reported to cause allergic contact dermatitis (52558,52581). Environmental exposure to goldenrod has been reported to cause an allergic reaction involving rhinoconjunctivitis and bronchial asthma in one case report (52558).

Pulmonary/Respiratory ...Environmental exposure to goldenrod has been reported to cause a delayed allergic reaction involving rhinoconjunctivitis and bronchial asthma in one case report of a 42 year-old woman who worked at a flower shop and was exposed to members of the Asteraceae/Compositae family, including goldenrod (52558).

(Read more about GOLDENROD)

General ...No adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted. There is some concern that hyssop oil has demonstrated toxicity at very low doses when administered orally in animal studies (1304).

(Read more about HYSSOP)

General ...Orally, senna is generally well-tolerated when used short-term in appropriate doses.
Most Common Adverse Effects:
Orally: Abdominal pain and discomfort, cramps, diarrhea, flatulence, nausea, fecal urgency, and urine discoloration.
Serious Adverse Effects (Rare):
Orally: Skin eruptions.

Cardiovascular ...Excessive use can cause potassium depletion and other electrolyte abnormalities (15425). In theory, this could cause potentially dangerous changes in heart rhythm. A small decrease in heart rate was seen in one clinical study (74587).

Dermatologic ...In adults, there are rare case reports of skin eruptions associated with senna, including erythema multiforme, fixed drug eruption, lichenoid reaction, toxic epidermal necrolysis, urticaria, photosensitivity, and contact dermatitis (96558). Infants and young children given senna products have experienced contact reactions on the buttocks due to prolonged exposure to stool while wearing a diaper overnight. These reactions range from erythema with small blisters, to large fluid-filled blisters with skin sloughing, as occurs with second degree burns (96559). In a case series of children treated with senna for chronic constipation, burn-like reactions occurred in 2.2%, typically with higher doses (mean 60 mg/day, range 35.2 to 150 mg/day) (96558,96559). These reactions can be avoided by giving senna early in the day, so that bowel movements occur at a time when diapers can be changed quickly (96559).

Gastrointestinal ...Orally, senna can cause abdominal pain and discomfort, cramps, bloating, flatulence, nausea, fecal urgency, and diarrhea (15427,15434,15435,15436,15439,15440,15441,105955). Chronic use has also been associated with "cathartic colon," radiographically diagnosed anatomical changes to the colon such as benign narrowing, colonic dilation, and loss of colonic folds (15428). The clinical relevance of these findings is unclear. Chronic use can also cause pseudomelanosis coli (pigment spots in intestinal mucosa) which is harmless, usually reverses with discontinuation, and is not associated with an increased risk of developing colorectal adenoma or carcinoma (6138). The cathartic properties of senna leaf are greater than the fruit (15430). Thus, the American Herbal Products Association only warns against long-term use of senna leaf (12).

Hepatic ...Chronic liver damage, portal vein thrombosis, and hepatitis have been reported following oral use of senna alkaloids, such as in tea made from senna leaves (13057,13095,41431,74560,74564,74584,105956). There is a case report of hepatitis in a female who consumed moderate amounts of senna tea. The patient was a poor metabolizer of cytochrome P450 2D6 (CYP2D6). It's thought that moderate doses of senna in this patient led to toxic hepatitis due to the patient's reduced ability to metabolize and eliminate the rhein anthrone metabolites of senna, which are thought to cause systemic toxicity (13057). There is also a case of liver failure, encephalopathy, and renal insufficiency in a female who consumed 1 liter/day of senna tea, prepared from 70 grams of dried senna fruit, over 3 years (13095). In another case report, a 3-year-old female presented with hepatitis that led to pancytopenia after drinking tea made from 2-3 grams dry senna leaves three times or more weekly for over one year (105956).

Immunologic ...In one case report, a 19-year-old male developed anaphylaxis with dyspnea, facial edema, and hives. This reaction was determined to be caused by the senna content in a specific combination product (Delgaxan Plus, Pompadour Ibérica) that the patient ingested (105957).

Musculoskeletal ...Hypertrophic osteoarthropathy, finger clubbing, cachexia, and tetany have been reported from excessive oral senna use in humans (15426,74580,74582,74620,74625).

Renal ...Nephrocalcinosis has been reported as a result of oral senna overuse (74582).

(Read more about SENNA)

General ...Uva ursi is generally well tolerated in low doses, short-term.
Most Common Adverse Effects:
Orally: Diarrhea, nausea, stomach upset, and vomiting.
Serious Adverse Effects (Rare):
Orally: At high doses (20 grams of dried herb), uva ursi has been reported to cause collapse, convulsions, cyanosis, delirium, shortness of breath, and tinnitus. Very high doses of 30 grams or more may be fatal.

Gastrointestinal ...Orally, uva ursi may cause nausea, vomiting, diarrhea, and stomach upset (92148). It can also irritate the gastrointestinal tract (19).

Genitourinary ...Orally, uva ursi may cause the urine to be greenish-brown. It may also cause irritation and inflammation of the urinary tract mucous membranes (18).

Hepatic ...Uva ursi may be hepatotoxic. Theoretically, chronic use, especially in children, can cause liver impairment due its hydroquinone and high tannin content (4,18).

Neurologic/CNS ...Orally, around 20 grams of uva ursi is reported to supply up to one gram of hydroquinone, which can theoretically cause convulsions and delirium (4).

Ocular/Otic ...Orally, uva ursi may potentially cause retinal toxicity due to its hydroquinone content, which reduces melanin synthesis. A 56-year-old female developed bilateral bull's-eye maculopathy, paracentral scotomas, and retinal thinning after 3 years of uva ursi tea ingestion (16900).
Taking around 20 grams of uva ursi orally is reported to supply up to one gram of hydroquinone, which can theoretically cause tinnitus (4).

Pulmonary/Respiratory ...Orally, around 20 grams of uva ursi is reported to supply up to one gram of hydroquinone, which can theoretically cause shortness of breath and cyanosis (4).

(Read more about UVA URSI)

General ...When used orally in high doses or long-term, yerba mate may be unsafe.
Most Common Adverse Effects:
Orally: Many of the adverse effects of yerba mate can be attributed to its caffeine content, such as diuresis, gastric irritation, insomnia, nausea, nervousness, restlessness, tachycardia, tachypnea, and tremors.
Serious Adverse Effects (Rare):
Orally: Cancer, hyperglycemia, ketosis, metabolic acidosis, sinus tachycardia. These adverse effects are more common with high doses or long-term use.

Cardiovascular ...Orally, yerba mate may cause cardiovascular-related adverse effects due to its caffeine content. High doses of mate providing 250 mg of caffeine can increase blood pressure. However, this doesn't seem to occur in people who habitually consume caffeine products (2722). Also, epidemiological research suggests that there is no association of caffeine consumption with incidence of hypertension (13739).
Due to its caffeine content, yerba mate may cause other adverse cardiovascular effects when used orally. These effects include tachycardia, quickened respiration, chest pain, premature heartbeat, arrhythmia, and hypertension (11832,11838,13735). Large doses of caffeine can also cause massive catecholamine release and subsequent sinus tachycardia (13734). There is also one report of venous occlusive disease associated with excessive, long-term mate consumption (5614).
Epidemiological research has found that regular caffeine intake of up to 400 mg per day, or approximately 8-10 cups of yerba mate, is not associated with an increased incidence of atrial fibrillation (38018,38076,91028,91034,97451,97453), atherosclerosis (38033), cardiac ectopy (91127), stroke (37804), ventricular arrhythmia (95948,97453), and cardiovascular disease in general (37805,98806).
Combining caffeine beverages such as yerba mate with ephedra may theoretically increase the risk of adverse cardiovascular events. There is one report of ischemic stroke in an athlete who consumed ephedra 40-60 mg, creatine monohydrate 6 grams, caffeine 400-600 mg, and a variety of other supplements daily for six weeks (1275).

Endocrine ...Yerba mate contains caffeine. Orally, large doses of caffeine can cause massive catecholamine release and subsequent metabolic acidosis, hyperglycemia, and ketosis (13734). Some evidence shows caffeine is associated with fibrocystic breast disease, breast cancer, and endometriosis in females. However, this is controversial since findings are conflicting (8043). Restricting caffeine in females with fibrocystic breast conditions doesn't seem to affect breast nodularity, swelling, or pain (8996). A population analysis of the Women's Health Initiative observational study has found no association between consumption of caffeine-containing beverages and the incidence of invasive breast cancer in models adjusted for demographic, lifestyle, and reproductive factors (108806). Also, a dose-response analysis of 2 low-quality observational studies has found that high consumption of caffeine is not associated with an increased risk of breast cancer (108807).

Gastrointestinal ...Orally, drinking yerba mate infusions has been associated with nausea and irritation of the stomach or oral mucosa in a small number of patients in one clinical study (86657). Yerba mate contains caffeine. Orally, caffeine can cause gastric irritation, nausea, and vomiting (11832,11838,13735). Caffeine-containing beverages can stimulate gastric secretion in humans, which may potentiate ulcer symptoms (36404). Some believe that long-term use of caffeine can cause withdrawal symptoms following discontinuation of use. However, the existence of caffeine withdrawal is controversial. Some researchers think that if it exists, it appears to be of little clinical significance (2723,11839). Gastrointestinal withdrawal symptoms such as nausea and vomiting have been described. However, these symptoms may be from nonpharmacological factors related to knowledge and expectation of effects. Clinically significant gastrointestinal symptoms caused by caffeine withdrawal may be uncommon (2723,11839).

Hematologic ...Yerba mate contains caffeine. Orally, caffeine can cause hypokalemia (11832,11838,13735).

Immunologic ...Yerba mate contains caffeine. Orally, caffeine can cause anaphylaxis in sensitive individuals, although true IgE-mediated caffeine allergy seems to be relatively rare (11315).

Musculoskeletal ...Yerba mate contains caffeine. Some epidemiological research suggests that caffeine may be associated with an increased risk of osteoporosis, but conflicting evidence exists. Caffeine can increase urinary excretion of calcium (2669,10202,11317). Females identified with a genetic variant of the vitamin D receptor appear to be at an increased risk for the detrimental effect of caffeine on bone mass (2669). However, moderate caffeine intake of less than 400 mg per day, or approximately 8-10 cups of yerba mate, does not seem to significantly increase osteoporosis risk in most postmenopausal adults with normal calcium intake (2669,6025,10202,11317,98806).

Some researchers believe that stopping regular use of caffeine may cause withdrawal symptoms such as muscle tension and muscle pains. However, these symptoms may be from nonpharmacological factors related to knowledge and expectation of effects (2723,11839). However, there is a case of withdrawal in a premature neonate following chronic parental drinking of yerba mate (86618). Symptoms included hypertonia in the limbs and brisk tendon reflexes. The authors indicated that high concentrations of caffeine and theobromine were found in the placenta, cord serum, neonatal urine, parental and neonatal hair, meconium, and breast milk. Although symptoms progressively disappeared at 84 hours of age, irritability was still occasionally present at discharge (24 days of age).

Neurologic/CNS ...Orally, drinking yerba mate infusions has been associated with insomnia in a small number of patients in one clinical study (86657). Yerba mate contains caffeine. Orally, caffeine can cause insomnia, nervousness, headache, anxiety, agitation, jitteriness, restlessness, ringing in the ears, tremors, delirium, and convulsions (11832,11838,13735). Caffeine may also exacerbate sleep disturbances in patients with acquired immunodeficiency syndrome (AIDS) (10204).
There is some concern that stopping regular use of caffeine may cause withdrawal symptoms such as headache, tiredness and fatigue, decreased energy, alertness, and attentiveness, drowsiness, decreased contentedness, depressed mood, difficulty concentrating, irritability, and lack of clear-headedness are typical of caffeine withdrawal (13738). Other symptoms such as delirium, nervousness, restlessness, and anxiety have been described. However, these symptoms may be from nonpharmacological factors related to knowledge and expectation of effects (2723,11839). However, there is a case of withdrawal in a premature neonate following chronic parental drinking of yerba mate (86618). Symptoms included jitteriness and irritability and a high-pitched cry. The authors indicated that high concentrations of caffeine and theobromine were found in the placenta, cord serum, neonatal urine, parental and neonatal hair, meconium, and breast milk. Although symptoms progressively disappeared at 84 hours of age, irritability was still occasionally present at discharge (24 days of age).

Oncologic ...Orally, the prolonged use of yerba mate or use of yerba mate in high doses (typically more than 1-2 liters daily) is associated with an increased risk of cancer, including mouth, esophageal, laryngeal, kidney, bladder, cervical, prostate, and lung cancer (1528,1529,1530,1531,11863,11864,92150,86595,86614,86700,86701). The effect seems to be cumulative and dose dependent. The risk of cancer with yerba mate use seems to increase if it is taken as a warm beverage. In 1991, the International Agency for Research on Cancer (IARC), reported that hot yerba mate drinking is a 2A agent, meaning it is probably carcinogenic for humans (92150). A statement published in 2016 stated there is no conclusive evidence for carcinogenicity when yerba mate is consumed at temperatures that are "not very hot" (95015). Drinking very hot beverages is believed to be a probable cause of esophageal cancer in humans (95015). Concomitant tobacco and alcohol use can increase risk 7-fold (11863).

Pulmonary/Respiratory ...Yerba mate contains caffeine. Orally, caffeine may cause tachypnea-induced respiratory alkalosis (11832,11838,13735). Some researchers think that stopping regular use of caffeine may cause withdrawal symptoms such as runny nose. However, this symptom may be from nonpharmacological factors related to knowledge and expectation of effects (2723,11839).

Renal ...Yerba mate contains caffeine. Orally, caffeine may cause diuresis (11832,11838,13735).

(Read more about YERBA MATE)