Common Names

  • Yerba mate
  • St. Bartholomew’s tea
  • Jesuit’s tea
  • Ilex
  • Hervea
  • Guyaki Paraguay tea
  • Chimarrão
  • Cimmaron

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

How It Works

Regularly drinking large amounts of mate tea can increase the risk for several types of cancers. 

Mate contains compounds that are thought to have stimulant effects. Mate products have been used both for weight loss and cancer prevention. Some lab studies suggest that mate can stop cancer cell growth, but it has not been shown to prevent or treat cancer in humans. Drinking large amounts of mate regularly is linked to increased risks of developing prostate, lung, bladder, esophageal, or head and neck cancers.

Purported Uses
  • To lose weight
    Small studies suggest that a product containing mate helped overweight subjects lose weight and may curb appetite. However, it is unclear if mate alone has these same effects and such results as well as safety of long-term use would need to be confirmed in larger studies. In addition, a large population study indicates that heavy mate drinkers tend to have higher bodyweight.
  • As a stimulant
    Because of its caffeine content, mate is a known stimulant.
  • To treat depression
    No scientific evidence supports this use.
  • To treat headaches
    Caffeine may increase the effect of some drugs for headache.
  • To relieve fatigue
    Because of its caffeine content, mate is a known stimulant. However, the increased risk of certain cancers likely outweighs any benefits.
  • To improve bone health
    Small studies are mixed on whether mate may have any benefit on bone health.
  • To promote urination
    Mate contains caffeine, which can increase urination.
  • To treat cancer
    Some compounds in mate appear to stop certain cancer cells from growing in the lab. However, this has not been studied in humans, and there are also other compounds in mate that can cause cancer.
Patient Warnings
  • High doses and prolonged use of mate tea are linked to increased risk of prostate, bladder, oral, esophageal, lung, and head and neck cancers.
  • Heavy alcohol use and/or smoking combined with long-term mate use additionally increases the risk of cancer.
  • Due to the caffeine content in mate, the following lab tests may be altered: Blood pressure, catecholamine levels, and bleeding time as measured by PT, PTT, or INR.
Do Not Take If
  • You are taking chemotherapy drugs: Mate may interfere with the actions of some drugs.
  • You are taking heart or blood pressure medications: Mate may increase the effects of these drugs or cause unwanted side-effects.
  • You are taking stimulant drugs (eg, Ritalin): Mate may increase the side-effects of these drugs.
  • You are taking drugs for depression: Mate may increase the side-effects of these drugs.
Side Effects

Sleep disruption, palpitations, increased heart rate, stomach upset, restlessness, anxiety

Case reports

  • Acute hepatitis: In a 21-year old American man, attributed to regular intake of mate tea once or twice daily for 4 months while visiting Argentina (37).
  • Liver failure: In an adult woman, linked to chronic long-term use of mate.
  • Withdrawal syndrome: Occurred in a newborn caused by a mother’s heavy intake of mate.
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For Healthcare Professionals

Scientific Name
Ilex paraguariensis
Clinical Summary

Mate is a plant native to South America. It is widely consumed as a hot beverage known as chimarrão, and is also used in traditional medicine. Mate is valued for its stimulatory effects and promoted as a dietary supplement for weight loss, cardiovascular diseases, and cancer prevention.

In vitro studies indicate that mate has antioxidant (1) and cardioprotective properties  (2). Animal models also suggest antiadipogenic and antilipidemic effects (3) (4).

Studies in humans are limited. One product containing mate was found to delay gastric emptying in overweight patients (5), and other preliminary studies in generally healthy women suggest consumption may have short-term effects on caloric intake and appetite regulation (6). In a large population of heavy mate drinkers, lower lipid levels but higher bodyweight was observed (34).

In a small cross-sectional study, long-term consumption of mate tea was associated with better bone health in postmenopausal women (7), but a more recent case-control study indicates a neutral effect on bone metabolism (35).

In various cancer models, constituents of mate exhibited proteasome (8) and topoisomerase (9) inhibitory properties, as well as anti-inflammatory and apoptotic effects (10) (11). However, no large-scale clinical studies have evaluated the safety and efficacy of mate in humans. Further, epidemiologic data indicate that chronic mate drinkers are at an increased risk of prostate (12), bladder (13) (14) (15), esophageal (16) (17), lung (18), and head and neck cancers (19). This risk appears to be additive when combined with chronic alcohol or tobacco use (20). Evidence also suggests that drinking very hot mate contributes to its carcinogenic effects  (33), although a meta-analysis found that mate consumed at more than 1 liter daily was associated with increased odds of developing upper aerodigestive tract cancers regardless of the temperature (36)

Purported Uses
  • Appetite suppression
  • Bone health
  • Depression
  • Fatigue
  • Headaches
  • Promote urination
  • Stimulant
  • Weight loss
Mechanism of Action

In vitro studies indicate that antioxidant and antimicrobial activity of mate may be due to its polyphenolic content (1) (22) (26), while cardioprotective effects occur through the regulation of nitric oxide (2).  Caffeine, theophylline, and theobromine are the xanthines in mate largely responsible for its stimulatory effects (21) (22) (23) (24) (25).

In animal models, mate regulates adipogenesis through the Wnt pathway (3), reduces lipid peroxidation, improves endothelial function and LPL and HL activities, and modulates lipogenic gene expression (4). Thermogenic properties have been related to enhanced expression of uncoupling proteins, while increased fatty acid oxidation is linked to AMPK phosphorylation in visceral adipose tissue (27).

Anticancer activities of mate extract can occur through proteasome (8) and topoisomerase (9) inhibition. It also reduced DNA damage from oxidative stress (1). In human colon cancer cells, saponins and phenolics in mate demonstrate anti-inflammatory activity and induce apoptosis through caspase activation (10) (11). However, other carcinogenic constituents in mate and high temperatures used for brewing could facilitate their solubility and absorption (19) (25) and thus explain associated increased cancer risks.


High doses and prolonged consumption of mate tea are associated with an increased risk of various cancers (12) (13) (14) (15) (16) (17) (18) (19) (36). Concomitant long-term alcohol or tobacco use further increases this risk (20).

  • Patients with hypertension, cardiac disorders, and anxiety should not consume mate (28) (29) (30).
  • Women who are pregnant or breastfeeding should not consume mate (31).
Adverse Reactions

Sleep disruption, arrhythmias, increased heart rate, stomach upset, and anxiety in vulnerable subjects (28) (29) (30).

Case Reports
Acute hepatitis:
In a 21-year old American man, attributed to regular ingestion of mate tea once or twice daily for 4 months while visiting Argentina (37).

Hepatic veno-occlusive disease/liver failure: In an adult woman, linked to the chronic long-term use of mate that contained small amounts of pyrrolizidine alkaloids (32).

Neonatal withdrawal syndrome: Jitteriness, irritability, high-pitched cry, limb hypertonia, and brisk tendon reflexes consistent with neonatal withdrawal syndrome reported in a premature newborn whose mother drank mate during pregnancy. Caffeine and theobromine were detected in high concentrations across various maternal and neonatal samples including breast milk and neonatal urine and hair. Symptoms progressively disappeared by 84 hours of age. However, intermittent irritability was still present at 24 days when the newborn was discharged. Considerable, progressive, and constant reduction of mate consumption to a maximum of 2 cups per day for the duration of breastfeeding was advised (31).

Herb-Drug Interactions

Chemotherapy: Due to its antioxidant activity, mate may interfere with some chemotherapy drugs (1).
Stimulant, cardiac, hypertension, or antidepressant drugs: Due to its caffeine content, mate may interact with these drugs, although specific interactions have not been studied.

Herb Lab Interactions

Due to the caffeine content in mate, the following lab tests may be altered:

  • Blood pressure
  • Catecholamine levels
  • Bleeding time as measured by PT, aPTT, or INR
Dosage (OneMSK Only)
  1. Miranda DD, Arcari DP, Pedrazzoli J, Jr., et al. Protective effects of mate tea (Ilex paraguariensis) on H2O2-induced DNA damage and DNA repair in mice. Mutagenesis. Jul 2008;23(4):261-265.
  2. Schinella G, Fantinelli JC, Mosca SM. Cardioprotective effects of Ilex paraguariensis extract: evidence for a nitric oxide-dependent mechanism. Clin Nutr. Jun 2005;24(3):360-366.
  3. Arcari DP, Santos JC, Gambero A, et al. The in vitro and in vivo effects of yerba mate (Ilex paraguariensis) extract on adipogenesis. Food Chem. Nov 15 2013;141(2):809-815.
  4. Gao H, Long Y, Jiang X, et al. Beneficial effects of Yerba Mate tea (Ilex paraguariensis) on hyperlipidemia in high-fat-fed hamsters. Exp Gerontol. Jun 2013;48(6):572-578.
  5. Andersen T, Fogh J. Weight loss and delayed gastric emptying following a South American herbal preparation in overweight patients. J Hum Nutr Diet. Jun 2001;14(3):243-250.
  6. Harrold JA, Hughes GM, O’Shiel K, et al. Acute effects of a herb extract formulation and inulin fibre on appetite, energy intake and food choice. Appetite. Mar 2013;62:84-90.
  7. Conforti AS, Gallo ME, Saravi FD. Yerba Mate (Ilex paraguariensis) consumption is associated with higher bone mineral density in postmenopausal women. Bone. Jan 2012;50(1):9-13.
  8. Arbiser JL, Li XC, Hossain CF, et al. Naturally occurring proteasome inhibitors from mate tea (Ilex paraguayensis) serve as models for topical proteasome inhibitors. J Invest Dermatol. Aug 2005;125(2):207-212.
  9. Gonzalez de Mejia E, Song YS, Ramirez-Mares MV, et al. Effect of yerba mate (Ilex paraguariensis) tea on topoisomerase inhibition and oral carcinoma cell proliferation. J Agric Food Chem. Mar 23 2005;53(6):1966-1973.
  10. Puangpraphant S, Berhow MA, Vermillion K, et al. Dicaffeoylquinic acids in Yerba mate (Ilex paraguariensis St. Hilaire) inhibit NF-kappaB nucleus translocation in macrophages and induce apoptosis by activating caspases-8 and -3 in human colon cancer cells. Mol Nutr Food Res. Oct 2011;55(10):1509-1522.
  11. Puangpraphant S, Berhow MA, de Mejia EG. Mate (Ilex paraguariensis St. Hilaire) saponins induce caspase-3-dependent apoptosis in human colon cancer cells in vitro. Food Chem. 2011;125(4):1171-1178.
  12. Deneo-Pellegrini H, Ronco AL, De Stefani E, et al. Food groups and risk of prostate cancer: a case-control study in Uruguay. Cancer Causes Control. Jul 2012;23(7):1031-1038.
  13. De Stefani E, Correa P, Fierro L, et al. Black tobacco, mate, and bladder cancer. A case-control study from Uruguay. Cancer. Jan 15 1991;67(2):536-540.
  14. De Stefani E, Boffetta P, Deneo-Pellegrini H, et al. Non-alcoholic beverages and risk of bladder cancer in Uruguay. BMC Cancer. 2007;7:57.
  15. Bates MN, Hopenhayn C, Rey OA, et al. Bladder cancer and mate consumption in Argentina: a case-control study. Cancer Lett. Feb 8 2007;246(1-2):268-273.
  16. Szymanska K, Matos E, Hung RJ, et al. Drinking of mate and the risk of cancers of the upper aerodigestive tract in Latin America: a case-control study. Cancer Causes Control. Nov 2010;21(11):1799-1806.
  17. Pintos J, Franco EL, Oliveira BV, et al. Mate, coffee, and tea consumption and risk of cancers of the upper aerodigestive tract in southern Brazil. Epidemiology. Nov 1994;5(6):583-590.
  18. De Stefani E, Fierro L, Correa P, et al. Mate drinking and risk of lung cancer in males: a case-control study from Uruguay. Cancer Epidemiol Biomarkers Prev. Jul 1996;5(7):515-519.
  19. Goldenberg D, Lee J, Koch WM, et al. Habitual risk factors for head and neck cancer. Otolaryngol Head Neck Surg. Dec 2004;131(6):986-993.
  20. Loria D, Barrios E, Zanetti R. Cancer and yerba mate consumption: a review of possible associations. Rev Panam Salud Publica. Jun 2009;25(6):530-539.
  21. Bojic M, Simon Haas V, Saric D, et al. Determination of Flavonoids, Phenolic Acids, and Xanthines in Mate Tea (Ilex paraguariensis St.-Hil.). J Anal Methods Chem. 2013;2013:658596.
  22. Prado Martin JG, Porto E, de Alencar SM, et al. Antimicrobial activity of yerba mate (Ilex paraguariensis St. Hil.) against food pathogens. Rev Argent Microbiol. Apr-Jun 2013;45(2):93-98.
  23. Coelho GC, Gnoatto SB, Bassani VL, et al. Quantification of saponins in extractive solution of mate leaves (Ilex paraguariensis A. St. Hil.). J Med Food. Apr 2010;13(2):439-443.
  24. Milioli EM, Cologni P, Santos CC, et al. Effect of acute administration of hydroalcohol extract of Ilex paraguariensis St Hilaire (Aquifoliaceae) in animal models of Parkinson’s disease. Phytother Res. Aug 2007;21(8):771-776.
  25. Kamangar F, Schantz MM, Abnet CC, et al. High levels of carcinogenic polycyclic aromatic hydrocarbons in mate drinks. Cancer Epidemiol Biomarkers Prev. May 2008;17(5):1262-1268.
  26. Chandra S, De Mejia Gonzalez E. Polyphenolic compounds, antioxidant capacity, and quinone reductase activity of an aqueous extract of Ardisia compressa in comparison to mate (Ilex paraguariensis) and green (Camellia sinensis) teas. J Agric Food Chem. Jun 2 2004;52(11):3583-3589.
  27. Pang J, Choi Y, Park T. Ilex paraguariensis extract ameliorates obesity induced by high-fat diet: potential role of AMPK in the visceral adipose tissue. Arch Biochem Biophys. Aug 15 2008;476(2):178-185.
  28. Bonnet M, Tancer M, Uhde T, et al. Effects of caffeine on heart rate and QT variability during sleep. Depress Anxiety. 2005;22(3):150-155.
  29. Childs E, Hohoff C, Deckert J, et al. Association between ADORA2A and DRD2 polymorphisms and caffeine-induced anxiety. Neuropsychopharmacology. Nov 2008;33(12):2791-2800.
  30. Cohen PA, Ernst E. Safety of herbal supplements: a guide for cardiologists. Cardiovasc Ther. Aug 2010;28(4):246-253.
  31. Martin I, Lopez-Vilchez MA, Mur A, et al. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit. Feb 2007;29(1):127-129.
  32. McGee J, Patrick RS, Wood CB, et al. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol. Sep 1976;29(9):788-794.
  33. Loomis D, Guyton KZ, Grosse Y, et al. Carcinogenicity of drinking coffee, mate, and very hot beverages. Lancet Oncol. Jul 2016;17(7):877-878.
  34. Chaves G, Britez N, Oviedo G, et al. Heavy drinkers of Ilex paraguariensis beverages show lower lipid profiles but higher body weight. Phytother Res. Jun 2018;32(6):1030-1038.
  35. da Veiga DTA, Bringhenti R, Bolignon AA, et al. The yerba mate intake has a neutral effect on bone: A case-control study in postmenopausal women. Phytother Res. Jan 2018;32(1):58-64.
  36. Mello FW, Scotti FM, Melo G, et al. Mate consumption association with upper aerodigestive tract cancers: A systematic review and meta-analysis. Oral Oncol. Jul 2018;82:37-47.
  37. Rodriguez EA, Teixeira Yokoda R, Payton DE, et al. Acute Hepatitis Secondary to the Use of Ilex paraguariensis (Mate Tea): A Case Report and Review of Literature. Case Reports Hepatol. 2019;2019:8459205.
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