Herb & supplement monograph

Yerba Mate Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Yerba Mate interacts with medications. The heart of this page is the interaction list — every drug Yerba Mate is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Yerba Mate is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Yerba Mate Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Yerba Mate drug interaction is low for most people, since nearly all concerns come from its caffeine content and remain theoretical. Only a small handful of the many listed interactions are rated major, and most of the rest are minor or backed by limited evidence.

Interactions deserving the most attention

The clearest concern is combining yerba mate with ephedrine, since caffeine plus this stimulant has been linked to serious effects like dangerously high blood pressure and heart problems. Cimetidine is well documented to slow the body's clearance of caffeine, which can amplify jitteriness, fast heart rate, and other caffeine effects; fluvoxamine, disulfiram, and estrogens can do something similar. Animal research also suggests caffeine might weaken seizure medications such as carbamazepine and phenytoin, so anyone whose seizure control depends on these medicines should be thoughtful about heavy yerba mate use.

What the rest of the list means

The long list of interactions reflects one simple fact: yerba mate contains caffeine, so almost any medicine affected by caffeine gets counted. Most of these entries are theoretical, drawn from lab or animal studies of how caffeine is processed, and several predicted effects have never been shown to cause meaningful problems in people.

Check your medications against Yerba Mate

Based on HelloPharmacist’s Yerba Mate interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Yerba Mate

1087 medications have a known interaction with Yerba Mate, graded by severity. Select any drug for the full evidence-based detail.

8 major interactions. These combinations can be clinically significant — best avoided, or used only with close professional supervision. Always check with your pharmacist before combining them with Yerba Mate.

2,830 drugs
Aminophylline, Amobarbital, EphedrineAmesec› Carbetapentane Tannate, Chlorpheniramine Tannate, Ephedrine Tannate, Phenylephrine TannateQuadratuss, Ry Tuss, Rynatuss, Tri Tannate Plus› Dyphylline, Ephedrine, Guaifenesin, PhenobarbitalLufyllin-EPG› Ephedrine, Guaifenesin (otc Drug)Ephedrine Formula 400, Ephedrine Plus Tabs› Ephedrine, Guaifenesin, Phenobarbital, TheophyllineMudrane GG› Ephedrine, Hydroxyzine, TheophyllineAmi Rax, Marax› Ephedrine, Phenobarbital, Potassium Iodide, TheophyllineMudrane, Quadrinal› Ephedrine, Phenobarbital, TheophyllineTedral› AbciximabReoPro› AbrocitinibCibinqo› AcenocoumarolSintrom› Acetaminophen, AspirinGemnisyn› Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine› Acetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu› Acetaminophen, Butalbital, CaffeineEsgic, Esgic Plus, Fiogesic, Fioricet, Repan, Tecnal +1 more› Acetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine› Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound› Acetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more› Acetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3› Acetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS› Acetaminophen, Caffeine, IsomethepteneMigralam› Acetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual› Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex› Acetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief› Acetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength› Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG› Acetaminophen, Chlorpheniramine, PhenylephrineAlka-Seltzer PLUS, Histex SR, Protid› Acetaminophen, Chlorpheniramine, Phenylephrine, SalicylamideRhinogesic, Rhinogesic JR› Acetaminophen, Chlorpheniramine, PhenylpropanolamineAlumadrine, Conex, Sinadrin Max Strength, Sinulin› Acetaminophen, Chlorpheniramine, Phenylpropanolamine, OpiumHista-Derfule›
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Yerba Mate combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Yerba Mate affects

Every type of medication (drug category) Yerba Mate is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 43 drug categories Yerba Mate interacts with
EphedrineAdenosine (adenocard)Anticoagulant/antiplatelet DrugsBenzodiazepinesBeta-adrenergic AgonistsCarbamazepine (tegretol)Cimetidine (tagamet)Clozapine (clozaril)Dipyridamole (persantine)Disulfiram (antabuse)Diuretic DrugsEstrogensEthosuximide (zarontin)Felbamate (felbatol)Flutamide (eulexin)Fluvoxamine (luvox)LithiumMidazolam (versed)Monoamine Oxidase Inhibitors (maois)NicotinePentobarbital (nembutal)Phenobarbital (luminal)PhenylpropanolaminePhenytoin (dilantin)Pioglitazone (actos)Quinolone AntibioticsRiluzole (rilutek)Stimulant DrugsTheophyllineValproateVerapamil (calan, Others)Alcohol (ethanol)Antidiabetes DrugsContraceptive DrugsCytochrome P450 1a2 (cyp1a2) InhibitorsCytochrome P450 3a4 (cyp3a4) SubstratesFluconazole (diflucan)Metformin (glucophage)Methoxsalen (oxsoralen)Mexiletine (mexitil)Terbinafine (lamisil)Tiagabine (gabitril)Ticlopidine (ticlid)
Ephedrine

Theoretically, the caffeine in yerba mate might increase the risk for stimulant adverse effects when used concomitantly with ephedrine.
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.

Likelihood Probable Evidence D
Adenosine (Adenocard)

Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of adenosine and interfere with its use prior to stress testing.
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. 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. 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. However, methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Possible Evidence B
Anticoagulant/Antiplatelet Drugs

Theoretically, the caffeine in yerba mate may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
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; however, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Benzodiazepines

Theoretically, the caffeine in yerba mate might reduce the efficacy of benzodiazepines.
Yerba mate contains caffeine. Caffeine can antagonize the anxiolytic effects of benzodiazepines.

Likelihood Probable Evidence D
Beta-Adrenergic Agonists

Theoretically, the caffeine in yerba mate might increase the cardiac inotropic effects of beta-agonists, especially if taken in large amounts.
Yerba mate contains caffeine. Caffeine can increase cardiac inotropic effects of beta-agonists.

Likelihood Probable Evidence D
Carbamazepine (Tegretol)

Theoretically, the caffeine in yerba mate might reduce the effects of carbamazepine and increase the risk for convulsions.
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. 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.

Likelihood Possible Evidence B
Cimetidine (Tagamet)

Theoretically, cimetidine might increase the levels and adverse effects of the caffeine contained in yerba mate.
Yerba mate contains caffeine. Cimetidine decreases caffeine clearance by 31% to 42%.

Likelihood Likely Evidence B
Clozapine (Clozaril)

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of clozapine and acutely exacerbate psychotic symptoms.
Yerba mate contains caffeine. Caffeine might increase the effects and toxicity of clozapine. Caffeine doses of 400-1000 mg per day inhibit clozapine metabolism. 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.

Likelihood Possible Evidence B
Dipyridamole (Persantine)

Theoretically, the caffeine in yerba mate might decrease the vasodilatory effects of dipyridamole and interfere with its use prior to stress testing.
Yerba mate contains caffeine. Caffeine inhibits dipyridamole-induced vasodilation. Still, some researchers recommend that methylxanthines, such as caffeine, as well as methylxanthine-containing products, should be stopped 24 hours prior to pharmacological stress. Methylxanthines appear more likely to interfere with dipyridamole (Persantine) than adenosine-induced stress testing.

Likelihood Probable Evidence B
Disulfiram (Antabuse)

Theoretically, disulfiram might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Disulfiram decreases the rate of caffeine clearance.

Likelihood Probable Evidence D
Diuretic Drugs

Theoretically, the caffeine in yerba mate might increase the risk of hypokalemia when used concomitantly with other diuretics.
Yerba mate contains caffeine. Caffeine, especially in excessive amounts, can reduce potassium levels due to stimulation of the sodium-potassium pump. Diuretics can also cause lower potassium levels.

Likelihood Possible Evidence D
Estrogens

Theoretically, estrogens might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Estrogen inhibits caffeine metabolism.

Likelihood Probable Evidence B
Ethosuximide (Zarontin)

Theoretically, the caffeine in yerba mate might reduce the effects of ethosuximide and increase the risk for convulsion.
Yerba mate contains caffeine. Animal research shows that caffeine 92.4 mg/kg can decrease the anticonvulsant activity of ethosuximide. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Felbamate (Felbatol)

Theoretically, the caffeine in yerba mate might reduce the effects of felbamate and increase the risk for convulsion.
Yerba mate contains caffeine. Animal research shows that a high dose of caffeine 161.7 mg/kg can decreases the anticonvulsant activity of felbamate. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Flutamide (Eulexin)

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of flutamide.
Yerba mate contains caffeine. In vitro evidence suggests that caffeine can inhibit the metabolism of flutamide. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Fluvoxamine (Luvox)

Theoretically, fluvoxamine might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Fluvoxamine reduces caffeine metabolism.

Likelihood Probable Evidence D
Lithium

Theoretically, abrupt withdrawal of the caffeine in yerba mate might increase serum lithium levels.
Yerba mate contains caffeine, which has diuretic activity. When abruptly discontinued, it might alter the clearance of lithium. There are two case reports of lithium tremor that worsened upon abrupt coffee withdrawal.

Likelihood Probable Evidence D
Midazolam (Versed)

Theoretically, use of yerba mate with midazolam might increase midazolam metabolite levels and adverse effects.
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).

Likelihood Possible Evidence D
Monoamine Oxidase Inhibitors (Maois)

Theoretically, the caffeine in yerba mate might increase risk of a hypertensive crisis when used concomitantly with MAOIs.
Yerba mate contains caffeine. Caffeine has been shown to inhibit monoamine oxidase (MAO) A and B in laboratory studies. Concomitant intake of large amounts of caffeine with MAOIs might precipitate a hypertensive crisis. In a case report, a patient that consumed 10-12 cups of caffeinated coffee and took the MAOI tranylcypromine presented with severe hypertension. Hypertension was resolved after the patient switched to drinking decaffeinated coffee.

Likelihood Possible Evidence D
Nicotine

Theoretically, the caffeine in yerba mate might increase risk of hypertension when used concomitantly with nicotine.
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.

Likelihood Probable Evidence D
Pentobarbital (Nembutal)

Theoretically, the caffeine in yerba mate might decrease the effects of pentobarbital.
The caffeine in yerba mate might negate the hypnotic effects of pentobarbital.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

Theoretically, the caffeine in yerba mate might reduce the effects of phenobarbital and increase the risk for convulsions.
Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenobarbital. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Phenylpropanolamine

Theoretically, phenylpropanolamine might increase the risk of hypertension as well as the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Concomitant use of phenylpropanolamine and caffeine might cause an additive increase in blood pressure. Phenylpropanolamine also seems to increase caffeine serum levels.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Theoretically, the caffeine in yerba mate might reduce the effects of phenytoin and increase the risk for convulsions.
Yerba mate contains caffeine. Animal research suggests that caffeine can decrease the anticonvulsant activity of phenytoin. 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.

Likelihood Possible Evidence B
Pioglitazone (Actos)

Theoretically, the caffeine in yerba mate might increase the levels and clinical effects of pioglitazone.
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. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, quinolone antibiotics might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Quinolones (also called fluoroquinolones) can decrease caffeine clearance by inhibiting cytochrome P450 1A2 (CYP1A2) enzyme.

Likelihood Probable Evidence B
Riluzole (Rilutek)

Theoretically, concomitant use of riluzole and yerba mate might increase levels and adverse effects of both riluzole and the caffeine in yerba mate.
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.

Likelihood Possible Evidence D
Stimulant Drugs

Theoretically, concomitant use of stimulant drugs and yerba mate might increase stimulant adverse effects.
Yerba mate contains caffeine. Due to the CNS stimulant effects of the caffeine, concomitant use can increase the risk of adverse effects.

Likelihood Probable Evidence C
Theophylline

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of theophylline.
Yerba mate contains caffeine. Caffeine decreases theophylline clearance by 23% to 29%.

Likelihood Probable Evidence D
Valproate

Theoretically, the caffeine in yerba mate might reduce the effects of valproate and increase the risk for convulsions.
Yerba mate contains caffeine. Animal research shows that caffeine can decrease the anticonvulsant activity of valproate. However, the exact mechanism of this interaction is unclear.

Likelihood Possible Evidence D
Verapamil (Calan, Others)

Theoretically, verapamil might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Verapamil increases plasma caffeine concentrations by 25%.

Likelihood Possible Evidence D
Alcohol (Ethanol)

Theoretically, concomitant use of alcohol and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Alcohol reduces caffeine metabolism. Concomitant use of alcohol can increase caffeine serum concentrations and the risk of caffeine adverse effects.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, taking yerba mate with antidiabetes drugs might interfere with blood glucose control.
Yerba mate contains caffeine. Reports claim that caffeine might increase or decrease blood sugar.

Likelihood Unlikely Evidence B
Contraceptive Drugs

Theoretically, contraceptive drugs might increase the levels and adverse effects of the caffeine contained in yerba mate.
Yerba mate contains caffeine. Contraceptive drugs decrease the rate of caffeine clearance by 40% to 65%.

Likelihood Possible Evidence B
Cytochrome P450 1A2 (Cyp1A2) Inhibitors

Theoretically, concomitant use of CYP1A2 inhibitors and yerba mate might increase levels and adverse effects of the caffeine in yerba mate.
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.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, yerba mate might increase the levels and clinical effects of CYP3A4 substrates.
In vitro research shows that yerba mate extract inhibits CYP3A4 enzymes. Theoretically, taking yerba mate may increase levels and adverse effects of CYP3A4 substrates.

Likelihood Possible Evidence D
Fluconazole (Diflucan)

Theoretically, fluconazole might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Fluconazole decreases caffeine clearance by approximately 25%.

Likelihood Possible Evidence B
Metformin (Glucophage)

Theoretically, metformin might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Animal research suggests that metformin can reduce caffeine metabolism. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Methoxsalen (Oxsoralen)

Theoretically, methoxsalen might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Methoxsalen reduces caffeine metabolism.

Likelihood Possible Evidence B
Mexiletine (Mexitil)

Theoretically, mexiletine might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Mexiletine decreases caffeine elimination by approximately 50%.

Likelihood Possible Evidence B
Terbinafine (Lamisil)

Theoretically, terbinafine might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. Terbinafine decreases the rate of caffeine clearance by 19%.

Likelihood Possible Evidence B
Tiagabine (Gabitril)

Theoretically, the caffeine in yerba mate might increase the levels and adverse effects of tiagabine.
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.

Likelihood Possible Evidence D
Ticlopidine (Ticlid)

Theoretically, ticlopidine might increase the levels and adverse effects of the caffeine in yerba mate.
Yerba mate contains caffeine. In vitro research shows that ticlopidine can inhibit caffeine metabolism. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Monograph

Yerba Mate: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Yerba mate is a caffeine-containing herbal beverage from South America that is widely enjoyed for its stimulating, coffee-like effects. While it is rich in antioxidants and is being studied for weight, blood sugar, and cholesterol, strong human evidence for most health claims is limited. Drinking very hot mate over many years has been linked to higher risk of certain cancers, so enjoy it warm and in moderation.

Yerba Mate
Scientific name
Ilex paraguariensis
Family
Aquifoliaceae
Part used
Leaves and twigs
Common forms
Tea (loose leaf or bagged), capsules, tablets, liquid extracts, energy drinks
People commonly use it for
  • Energy and alertness
  • Weight loss
  • Mental focus
  • Digestive support
  • Antioxidant support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

Generally fine in moderate amounts, but it contains caffeine and very hot or heavy long-term use has health concerns.

PregnancyPossibly Unsafe

When used orally. Yerba mate is associated with an increased risk of cancer, including esophageal, kidney, bladder, cervical, prostate, lung, renal ce...

Read the full pregnancy detail
BreastfeedingPossibly Unsafe

When used orally. Yerba mate is associated with an increased risk of cancer, including esophageal, kidney, bladder, cervical, prostate, lung, renal ce...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Yerba mate comes from the leaves and twigs of Ilex paraguariensis, an evergreen shrub or tree that grows in parts of South America such as Argentina, Brazil, Paraguay, and Uruguay. For hundreds of years, people in these regions have dried and steeped the leaves to make a tea-like drink.

Mate is traditionally sipped warm from a hollow gourd through a metal straw, and sharing it is an important social custom. Today it is also sold as tea bags, loose leaf, capsules, and as an ingredient in energy drinks and weight-loss products.

People mainly drink yerba mate for an energy boost and mental alertness, much like coffee or green tea, because it naturally contains caffeine.

How it works

Yerba mate contains caffeine and related compounds (sometimes called methylxanthines) that stimulate the brain and nervous system, which is why it can make you feel more awake and focused.

The leaves are also rich in polyphenols and chlorogenic acids, which act as antioxidants in laboratory tests. Researchers think these compounds might affect inflammation, fat metabolism, blood sugar, and cholesterol.

It is important to know that much of this evidence comes from test-tube and animal studies, or small human trials. These findings do not always carry over to real-world health benefits in people.

Effectiveness

Does Yerba Mate work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 18 uses evaluated
18 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Yerba Mate, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 18 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Arrhythmia
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Athletic performance
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial for improving athletic performance.

Insufficient Reliable Evidence To Rate Chronic fatigue syndrome (CFS)
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Cognitive function
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial for improving cognitive function.

Insufficient Reliable Evidence To Rate Depression
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Diabetes
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in patients with diabetes.

Insufficient Reliable Evidence To Rate Dyslipidemia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in patients with dyslipidemia.

Insufficient Reliable Evidence To Rate Headache
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Heart failure
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Impaired glucose tolerance (Prediabetes)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in patients with prediabetes.

Insufficient Reliable Evidence To Rate Joint pain
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Kidney stones (nephrolithiasis)
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Mental alertness
Rating & evidence shown verbatim from Natural Medicines

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.

Insufficient Reliable Evidence To Rate Muscle strength
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate improves muscle strength.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in patients with obesity.

Insufficient Reliable Evidence To Rate Osteoporosis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in patients with osteoporosis.

Insufficient Reliable Evidence To Rate Parkinson Disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral yerba mate is beneficial in preventing Parkinson disease.

Insufficient Reliable Evidence To Rate Urinary tract infections (UTIs)
Rating & evidence shown verbatim from Natural Medicines

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.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

When consumed as a normal beverage in moderate amounts, yerba mate is generally considered acceptable for most healthy adults. Because it contains caffeine, people who are sensitive to stimulants, who have heart problems, high blood pressure, anxiety, or trouble sleeping should be cautious.

One notable concern is that drinking mate very hot, in large amounts, over many years has been linked to a higher risk of cancers of the mouth, throat, and esophagus. Letting the drink cool to a warm (not scalding) temperature may lower this risk. Heavy, lifelong, high-volume use is where most safety worries arise.

For pregnancy, it is best to limit caffeine, and high mate intake is not recommended without medical advice. For breastfeeding, caffeine passes into breast milk and can affect the baby, so limiting or avoiding mate is the safer choice. Children should generally avoid caffeinated mate. Always talk to your pharmacist or doctor before using it regularly, especially if you have a medical condition.

Side effects

Most side effects are related to caffeine and include jitteriness, nervousness, fast heartbeat, headache, upset stomach, and trouble sleeping. Drinking it too close to bedtime can disrupt sleep.

Larger doses can cause stomach upset or a laxative effect. Over the long term, very heavy and very hot mate drinking has been associated with an increased risk of certain cancers of the upper digestive tract.

Stop using it and seek medical care if you have chest pain, a very rapid or irregular heartbeat, or other concerning symptoms.

Yerba Mate: Reported Adverse Effects

Documented safety reports on Yerba Mate from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

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.

Reports by condition
Allergic rhinitis (hay fever) Immunologic

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

  1. Infante S, Baeza ML, Calvo M, et al. Anaphylaxis due to caffeine. Allergy 2003;58:681-2.
Anxiety Neurologic/CNS

Orally, drinking yerba mate infusions has been associated with insomnia in a small number of patients in one clinical study. Yerba mate contains caffeine. Orally, caffeine can cause insomnia, nervousness, headache, anxiety, agitation, jitteriness, restlessness, ringing in the ears, tremors, delirium, and convulsions. Caffeine may also exacerbate sleep disturbances in patients with acquired immunodeficiency syndrome (AIDS).

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. 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. However, there is a case of withdrawal in a premature neonate following chronic parental drinking of yerba mate. 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).

  1. de Morais, E. C., Stefanuto, A., Klein, G. A., Boaventura, B. C., de, Andrade F., Wazlawik, E., Di Pietro, P. F., Maraschin, M., and da Silva, E. L. Consumption of yerba mate ( Ilex paraguariensis ) improves serum lipid parameters in healthy dyslipidemic
  2. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html.
  3. Holmgren P, Norden-Pettersson L, Ahlner J. Caffeine fatalities--four case reports. Forensic Sci Int 2004;139:71-3.
  4. Leson CL, McGuigan MA, Bryson SM. Caffeine overdose in an adolescent male. J Toxicol Clin Toxicol 1988;26:407-15.
  5. Dreher HM. The effect of caffeine reduction on sleep quality and well-being in persons with HIV. J Psychosom Res 2003;54:191-8..
  6. Juliano LM, Griffiths RR. A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features. Psychopharmacology (Berl) 2004;176:1-29.
  7. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32.
  8. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61.
  9. Martin, I., Lopez-Vilchez, M. A., Mur, A., Garcia-Algar, O., Rossi, S., Marchei, E., and Pichini, S. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit. 2007;29(1):127-129.
Arrhythmia 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. Also, epidemiological research suggests that there is no association of caffeine consumption with incidence of hypertension.

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. Large doses of caffeine can also cause massive catecholamine release and subsequent sinus tachycardia. There is also one report of venous occlusive disease associated with excessive, long-term mate consumption.

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, atherosclerosis, cardiac ectopy, stroke, ventricular arrhythmia, and cardiovascular disease in general.

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.

  1. Nurminen ML, Niittynen L, Korpela R, Vapaatalo H. Coffee, caffeine and blood pressure: a critical review. Eur J Clin Nutr 1999;53:831-9.
  2. Winkelmayer WC, Stampfer MJ, Willett WC, Curhan GC. Habitual caffeine intake and the risk of hypertension in women. JAMA 2005;294:2330-5.
  3. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html.
  4. Holmgren P, Norden-Pettersson L, Ahlner J. Caffeine fatalities--four case reports. Forensic Sci Int 2004;139:71-3.
  5. Leson CL, McGuigan MA, Bryson SM. Caffeine overdose in an adolescent male. J Toxicol Clin Toxicol 1988;26:407-15.
  6. Benowitz NL, Osterloh J, Goldschlager N, et al. Massive catecholamine release from caffeine poisoning. JAMA 1982;248:1097-8.
  7. McGee J, Patrick RS, Wood CB, Blumgart LH. A case of veno-occlusive disease of the liver in Britain associated with herbal tea consumption. J Clin Pathol 1976;29:788-94.
  8. Conen, D., Chiuve, S. E., Everett, B. M., Zhang, S. M., Buring, J. E., and Albert, C. M. Caffeine consumption and incident atrial fibrillation in women. Am J Clin Nutr 2010;92(3):509-514.
  9. Gronroos, N. N. and Alonso, A. Diet and risk of atrial fibrillation - epidemiologic and clinical evidence -. Circ.J 2010;74(10):2029-2038.
  10. Caldeira D, Martins C, Alves LB, Pereira H, Ferreira JJ, Costa J. Caffeine does not increase the risk of atrial fibrillation: a systematic review and meta-analysis of observational studies. Heart. 2013;99(19):1383-9. doi: 10.1136/heartjnl-2013-303950. Re
  11. Cheng M, Hu Z, Lu X, Huang J, Gu D. Caffeine intake and atrial fibrillation incidence: dose response meta-analysis of prospective cohort studies. Can J Cardiol. 2014 Apr;30(4):448-54. doi: 10.1016/j.cjca.2013.12.026. Epub 2014 2. Review.
  12. Lagier D, Nee L, Guieu R, et al. Peri-operative oral caffeine does not prevent postoperative atrial fibrillation after heart valve surgery with cardiopulmonary bypass: a randomized controlled clinical trial. Eur J Anaesthesiol. 2018 Apr 26. [Epub ahead of
  13. Voskoboinik A, Kalman JM, Kistler PM. Caffeine and arrhythmias: time to grind the data. JACC: Clin Electrophysiol. 2018;4(4):425-32.
  14. Reis, J. P., Loria, C. M., Steffen, L. M., Zhou, X., van, Horn L., Siscovick, D. S., Jacobs, D. R., Jr., and Carr, J. J. Coffee, decaffeinated coffee, caffeine, and tea consumption in young adulthood and atherosclerosis later in life: the CARDIA study. A
  15. Dixit S, Stein PK, Dewland TA, Dukes JW, Vittinghoff E, Heckbert SR, Marcus GM. Consumption of Caffeinated Products and Cardiac Ectopy. J Am Heart Assoc. 2016 26;5(1). pii: e002503. doi: 10.1161/JAHA.115.002503.
  16. Lopez-Garcia, E., Rodriguez-Artalejo, F., Rexrode, K. M., Logroscino, G., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of stroke in women. Circulation 3-3-2009;119(8):1116-1123.
  17. Zuchinali P, Riberio PA, Pimentel M, da Rosa PR, Zimerman LI, Rohde LE. Effect of caffeine on ventricular arrhythmia: a systematic review and meta-analysis of experimental and clinical studies. Europace 2016 Feb;18(2):257-66.
  18. Zhang, W., Lopez-Garcia, E., Li, T. Y., Hu, F. B., and van Dam, R. M. Coffee consumption and risk of cardiovascular diseases and all-cause mortality among men with type 2 diabetes. Diabetes Care 2009;32(6):1043-1045.
  19. Wikoff D, Welsh BT, Henderson R, et al. Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food Chem Toxicol 2017;109:585-648.
  20. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
Bone loss 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. 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. 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.

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. However, there is a case of withdrawal in a premature neonate following chronic parental drinking of yerba mate. 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).

  1. Rapuri PB, Gallagher JC, Kinyamu HK, Ryschon KL. Caffeine intake increases the rate of bone loss in elderly women and interacts with vitamin D receptor genotypes. Am J Clin Nutr 2001;74:694-700.
  2. Massey LK. Is caffeine a risk factor for bone loss in the elderly? Am J Clin Nutr 2001;74:569-70.
  3. Massey LK, Whiting SJ. Caffeine, urinary calcium, calcium metabolism and bone. J Nutr 1993;123:1611-4.
  4. Lloyd T, Johnson-Rollings N, Eggli DF, et al. Bone status among postmenopausal women with different habitual caffeine intakes: a longitudinal investigation. J Am Coll Nutr 2000;19:256-61.
  5. Wikoff D, Welsh BT, Henderson R, et al. Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food Chem Toxicol 2017;109:585-648.
  6. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32.
  7. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61.
  8. Martin, I., Lopez-Vilchez, M. A., Mur, A., Garcia-Algar, O., Rossi, S., Marchei, E., and Pichini, S. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit. 2007;29(1):127-129.
Breast cancer Endocrine

Yerba mate contains caffeine. Orally, large doses of caffeine can cause massive catecholamine release and subsequent metabolic acidosis, hyperglycemia, and ketosis. Some evidence shows caffeine is associated with fibrocystic breast disease, breast cancer, and endometriosis in females. However, this is controversial since findings are conflicting. Restricting caffeine in females with fibrocystic breast conditions doesn't seem to affect breast nodularity, swelling, or pain. 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. 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.

  1. Benowitz NL, Osterloh J, Goldschlager N, et al. Massive catecholamine release from caffeine poisoning. JAMA 1982;248:1097-8.
  2. Ferrini RL, Barrett-Connor E. Caffeine intake and endogenous sex steroid levels in postmenopausal women. The Rancho Bernardo Study. Am J Epidemiol 1996:144:642-4.
  3. Horner NK, Lampe JW. Potential mechanisms of diet therapy for fibrocystic breast conditions show inadequate evidence of effectiveness. J Am Diet Assoc 2000;100:1368-80.
  4. Zheng KH, Zhu K, Wactawski-Wende J, et al. Caffeine intake from coffee and tea and invasive breast cancer incidence among postmenopausal women in the Women's Health Initiative. Int J Cancer 2021;149(12):2032-2044.
  5. Wang S, Li X, Yang Y, et al. Does coffee, tea and caffeine consumption reduce the risk of incident breast cancer? A systematic review and network meta-analysis. Public Health Nutr 2021;24(18):6377-6389.
Cancer 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. 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. 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". Drinking very hot beverages is believed to be a probable cause of esophageal cancer in humans. Concomitant tobacco and alcohol use can increase risk 7-fold.

  1. 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 1994;5:583-90.
  2. De Stefani E, Fierro L, Mendilaharsu M, et al. Meat intake, 'mate' drinking and renal cell cancer in Uruguay: a case-control study. Br J Cancer 1998;78:1239-43.
  3. De Stefani E, Correa P, Fierro L, et al. Black tobacco, mate, and bladder cancer. A case-control study from Uruguay. Cancer 1991;67:536-40.
  4. 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 1996;5:515-9.
  5. Goldenberg D, Golz A, Joachims HZ. The beverage mate: a risk factor for cancer of the head and neck. Head Neck 2003;25:595-601.
  6. Sewram V, De Stefani E, Brennan P, Boffetta P. Mate consumption and the risk of squamous cell esophageal cancer in uruguay. Cancer Epidemiol Biomarkers Prev 2003;12:508-13.
  7. Stefani ED, Moore M, Aune D, Deneo-Pellegrini H, Ronco AL, Boffetta P, et al. Maté consumption and risk of cancer: a multi-site case-control study in Uruguay. Asian Pac J Cancer Prev. 2011;12(4):1089-93.
  8. Bates, M. N., Rey, O. A., Biggs, M. L., Hopenhayn, C., Moore, L. E., Kalman, D., Steinmaus, C., and Smith, A. H. Case-control study of bladder cancer and exposure to arsenic in Argentina. Am J Epidemiol. 2-15-2004;159(4):381-389.
  9. Bates, M. N., Hopenhayn, C., Rey, O. A., and Moore, L. E. Bladder cancer and mate consumption in Argentina: a case-control study. Cancer Lett. 2-8-2007;246(1-2):268-273.
  10. De, Stefani E., Correa, P., Oreggia, F., Deneo-Pellegrini, H., Fernandez, G., Zavala, D., Carzoglio, J., Leiva, J., Fontham, E., and Rivero, S. Black tobacco, wine and mate in oropharyngeal cancer. A case-control study from Uruguay. Rev.Epidemiol.Sante P
  11. Vassallo, A., Correa, P., De, Stefani E., Cendan, M., Zavala, D., Chen, V., Carzoglio, J., and Deneo-Pellegrini, H. Esophageal cancer in Uruguay: a case-control study. J Natl.Cancer Inst. 1985;75(6):1005-1009.
  12. International Agency for Research on Cancer (IARC). IARC monographs evaluate drinking coffee, mate, and very hot beverages. https://www.iarc.fr/en/media-centre/pr/2016/pdfs/pr244_E.pdf. Accessed November 1, 2017.
Hypokalemia Hematologic

Yerba mate contains caffeine. Orally, caffeine can cause hypokalemia.

  1. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html.
  2. Holmgren P, Norden-Pettersson L, Ahlner J. Caffeine fatalities--four case reports. Forensic Sci Int 2004;139:71-3.
  3. Leson CL, McGuigan MA, Bryson SM. Caffeine overdose in an adolescent male. J Toxicol Clin Toxicol 1988;26:407-15.
Nausea and vomiting 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. Yerba mate contains caffeine. Orally, caffeine can cause gastric irritation, nausea, and vomiting. Caffeine-containing beverages can stimulate gastric secretion in humans, which may potentiate ulcer symptoms. 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. 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.

  1. de Morais, E. C., Stefanuto, A., Klein, G. A., Boaventura, B. C., de, Andrade F., Wazlawik, E., Di Pietro, P. F., Maraschin, M., and da Silva, E. L. Consumption of yerba mate ( Ilex paraguariensis ) improves serum lipid parameters in healthy dyslipidemic
  2. Institute of Medicine. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington, DC: National Academy Press, 2001. Available at: http://books.nap.edu/books/0309082587/html/index.html.
  3. Holmgren P, Norden-Pettersson L, Ahlner J. Caffeine fatalities--four case reports. Forensic Sci Int 2004;139:71-3.
  4. Leson CL, McGuigan MA, Bryson SM. Caffeine overdose in an adolescent male. J Toxicol Clin Toxicol 1988;26:407-15.
  5. ROTH, J. L. Clinical evaluation of the caffeine gastric analysis in duodenal ulcer patients. Gastroenterology 1951;19(2):199-215.
  6. Dews PB, Curtis GL, Hanford KJ, O'Brien CP. The frequency of caffeine withdrawal in a population-based survey and in a controlled, blinded pilot experiment. J Clin Pharmacol 1999;39:1221-32.
  7. Dews PB, O'Brien CP, Bergman J. Caffeine: behavioral effects of withdrawal and related issues. Food Chem Toxicol 2002;40:1257-61.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no official or standardized medicinal dose for yerba mate. Most people simply drink it as a tea, and the caffeine content varies depending on how it is prepared and how strong it is brewed.

If you use a capsule or extract product, follow the directions on the label and do not exceed the recommended amount. Keep your total daily caffeine from all sources in mind. If you are unsure how much is appropriate for you, check with your pharmacist or doctor, especially if you have heart, blood pressure, or sleep concerns.

Pregnancy & Breastfeeding

Yerba Mate & 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. 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. 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. High doses of caffeine throughout pregnancy have resulted in symptoms of caffeine withdrawal in newborn infants. Caffeine in doses of greater than 300 mg daily has also been associated with spontaneous abortion, premature delivery, and low birth weight, although one retrospective study found that consuming yerba mate tea during pregnancy was not associated with preterm or small for gestational age births. 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.

  1. 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 1994;5:583-90.
  2. De Stefani E, Fierro L, Mendilaharsu M, et al. Meat intake, 'mate' drinking and renal cell cancer in Uruguay: a case-control study. Br J Cancer 1998;78:1239-43.
  3. De Stefani E, Correa P, Fierro L, et al. Black tobacco, mate, and bladder cancer. A case-control study from Uruguay. Cancer 1991;67:536-40.
  4. 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 1996;5:515-9.
  5. Goldenberg D, Golz A, Joachims HZ. The beverage mate: a risk factor for cancer of the head and neck. Head Neck 2003;25:595-601.
  6. Sewram V, De Stefani E, Brennan P, Boffetta P. Mate consumption and the risk of squamous cell esophageal cancer in uruguay. Cancer Epidemiol Biomarkers Prev 2003;12:508-13.
  7. Stefani ED, Moore M, Aune D, Deneo-Pellegrini H, Ronco AL, Boffetta P, et al. Maté consumption and risk of cancer: a multi-site case-control study in Uruguay. Asian Pac J Cancer Prev. 2011;12(4):1089-93.
  8. Bates, M. N., Rey, O. A., Biggs, M. L., Hopenhayn, C., Moore, L. E., Kalman, D., Steinmaus, C., and Smith, A. H. Case-control study of bladder cancer and exposure to arsenic in Argentina. Am J Epidemiol. 2-15-2004;159(4):381-389.
  9. Bates, M. N., Hopenhayn, C., Rey, O. A., and Moore, L. E. Bladder cancer and mate consumption in Argentina: a case-control study. Cancer Lett. 2-8-2007;246(1-2):268-273.
  10. De, Stefani E., Correa, P., Oreggia, F., Deneo-Pellegrini, H., Fernandez, G., Zavala, D., Carzoglio, J., Leiva, J., Fontham, E., and Rivero, S. Black tobacco, wine and mate in oropharyngeal cancer. A case-control study from Uruguay. Rev.Epidemiol.Sante P
  11. Vassallo, A., Correa, P., De, Stefani E., Cendan, M., Zavala, D., Chen, V., Carzoglio, J., and Deneo-Pellegrini, H. Esophageal cancer in Uruguay: a case-control study. J Natl.Cancer Inst. 1985;75(6):1005-1009.
  12. Nawrot P, Jordan S, Eastwood J, et al. Effects of caffeine on human health. Food Addit Contam 2003;20:1-30.
  13. Wikoff D, Welsh BT, Henderson R, et al. Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children. Food Chem Toxicol 2017;109:585-648.
  14. The National Toxicology Program (NTP). Caffeine. Center for the Evaluation of Risks to Human Reproduction (CERHR). Available at: http://cerhr.niehs.nih.gov/common/caffeine.html.
  15. McGowan JD, Altman RE, Kanto WP Jr. Neonatal withdrawal symptoms after chronic maternal ingestion of caffeine. South Med J 1988;81:1092-4..
  16. Martin, I., Lopez-Vilchez, M. A., Mur, A., Garcia-Algar, O., Rossi, S., Marchei, E., and Pichini, S. Neonatal withdrawal syndrome after chronic maternal drinking of mate. Ther Drug Monit. 2007;29(1):127-129.
  17. Klebanoff MA, Levine RJ, DerSimonian R, et al. Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. N Engl J Med 1999;341:1639-44.
  18. Fernandes O, Sabharwal M, Smiley T, et al. Moderate to heavy caffeine consumption during pregnancy and relationship to spontaneous abortion and abnormal fetal growth: a meta-analysis. Reprod Toxicol 1998;12:435-44.
  19. Santos IS, Matijasevich A, Valle NC. Mate drinking during pregnancy and risk of preterm and small for gestational age birth. J Nutr 2005;135:1120-3.
  20. Gleason JL, Sundaram R, Mitro SD, et al. Association of maternal caffeine consumption during pregnancy with child growth. JAMA Netw Open. 2022;5(10):e2239609.

Yerba Mate & Breastfeeding

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. 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.

  1. 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 1994;5:583-90.
  2. De Stefani E, Fierro L, Mendilaharsu M, et al. Meat intake, 'mate' drinking and renal cell cancer in Uruguay: a case-control study. Br J Cancer 1998;78:1239-43.
  3. De Stefani E, Correa P, Fierro L, et al. Black tobacco, mate, and bladder cancer. A case-control study from Uruguay. Cancer 1991;67:536-40.
  4. 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 1996;5:515-9.
  5. Goldenberg D, Golz A, Joachims HZ. The beverage mate: a risk factor for cancer of the head and neck. Head Neck 2003;25:595-601.
  6. Sewram V, De Stefani E, Brennan P, Boffetta P. Mate consumption and the risk of squamous cell esophageal cancer in uruguay. Cancer Epidemiol Biomarkers Prev 2003;12:508-13.
  7. Stefani ED, Moore M, Aune D, Deneo-Pellegrini H, Ronco AL, Boffetta P, et al. Maté consumption and risk of cancer: a multi-site case-control study in Uruguay. Asian Pac J Cancer Prev. 2011;12(4):1089-93.
  8. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001;108:776-89.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 123 references that drive our Yerba Mate monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Harder S, Fuhr U, Staib AH, Wolff T. Ciprofloxacin-caffeine: a drug interaction established using in vivo and in vitro investigations. Am J Med 1989;87:89S-91S. PubMed
  3. Carbo M, Segura J, De la Torre R, et al. Effect of quinolones on caffeine disposition. Clin Pharmacol Ther 1989;45:234-40. PubMed
  4. Healy DP, Polk RE, Kanawati L, et al. Interaction between oral ciprofloxacin and caffeine in normal volunteers. Antimicrob Agents Chemother 1989;33:474-8. PubMed
  5. Mester R, Toren P, Mizrachi I, et al. Caffeine withdrawal increases lithium blood levels. Biol Psychiatry 1995;37:348-50. PubMed
  6. Jefferson JW. Lithium tremor and caffeine intake: two cases of drinking less and shaking more. J Clin Psychiatry 1988;49:72-3.
  7. Joeres R, Klinker H, Heusler H, et al. Influence of mexiletine on caffeine elimination. Pharmacol Ther 1987;33:163-9. PubMed
  8. Vahedi K, Domingo V, Amarenco P, Bousser MG. Ischemic stroke in a sportsman who consumed MaHuang extract and creatine monohydrate for bodybuilding. J Neurol Neurosurg Psychiatr 2000;68:112-3.
  9. 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 1994;5:583-90.
  10. De Stefani E, Fierro L, Mendilaharsu M, et al. Meat intake, 'mate' drinking and renal cell cancer in Uruguay: a case-control study. Br J Cancer 1998;78:1239-43. PubMed
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  15. Klebanoff MA, Levine RJ, DerSimonian R, et al. Maternal serum paraxanthine, a caffeine metabolite, and the risk of spontaneous abortion. N Engl J Med 1999;341:1639-44. PubMed
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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Brand directory

Brands that make products with Yerba Mate

33 brands in our database make a supplement containing Yerba Mate.

Product directory

Supplement products with Yerba Mate

68 products in our database contain Yerba Mate. Open any to see its full ingredient list and every drug interaction we check.

Battle Fuel by MusclePharm Capsule 126 Capsule(s) View ingredients & interactions Beet Active Passion Fruit by Nutrology Powder 5.5 oz · 156 Gram(s) View ingredients & interactions Brain Boost Chocolate Mocha by Organic Muscle Powder 5.64 Ounce(s) · 160 Gram(s) View ingredients & interactions Brain Energy by Host Defense Mushrooms MycoBotanicals Powder 3.5 Ounce(s) · 100 Gram(s) View ingredients & interactions Burn by Motiv-8 Capsule 60 Veg Capsule(s) View ingredients & interactions Daily Greens by Huel Powder 450 Gram(s) View ingredients & interactions Dr. Cutler's Ultimate Age Defense by True Health Capsule 60 Capsule(s) View ingredients & interactions ELXR by Loomis Enzymes Capsule 180 Capsule(s) View ingredients & interactions ELXR by Loomis Enzymes Capsule 180 Capsule(s) View ingredients & interactions Energex by NewtonEverett Capsule 90 Vegetarian Capsule(s) View ingredients & interactions Energy Go Stix Berry by ShapeRite by 4Life Powder 30 Powder Pack(s) View ingredients & interactions Extra Strength Yerba Mate 4:1 Extract Powder by TerraVita Premium Collection Powder 1 Ounce(s) View ingredients & interactions Extra Strength Yerba Mate 4:1 Extract Powder by TerraVita Premium Collection Powder 4 Ounce(s) View ingredients & interactions FitMiss Burn by MusclePharm Capsule 90 Capsule(s) View ingredients & interactions Focus-R by LifeSeasons Therapeutics Capsule 60 Veg Capsule(s) View ingredients & interactions Hoodiadrene by NewtonEverett Capsule 150 Vegetarian Capsule(s) View ingredients & interactions Hoodiadrene 1825 mg by NewtonEverett Capsule 150 Vegetarian Capsule(s) View ingredients & interactions Jump-Start Energy Blend Citrus Punch Flavor by BodyMelt Powder 0.79 Pound(s) · 360 Gram(s) View ingredients & interactions Levare by Ultimaxx Health Capsule 24 Capsule(s) View ingredients & interactions Levare by Ultimaxx Health Capsule 90 Capsule(s) View ingredients & interactions Levare by Ultimaxx Health Capsule 60 Capsule(s) View ingredients & interactions MetaboBOOST by Wonder Laboratories Capsule 90 Capsule(s) View ingredients & interactions MetaboBOOST by Wonder Laboratories Capsule 90 Capsule(s) View ingredients & interactions MetaboBOOST by Wonder Laboratories Capsule 90 Capsule(s) View ingredients & interactions
Pharmacist Counseling Corner

Yerba Mate: Common Questions

What is Yerba Mate used for, and does it work?
People use Yerba Mate for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Yerba Mate interact with prescription medications?
Yes. We list 1087 medications with a known interaction with Yerba Mate, including 8 rated major. Use the checker above to see how Yerba Mate interacts with a specific drug.
How are Yerba Mate interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Yerba Mate with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Yerba Mate interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
Does Yerba Mate have caffeine?
Yes. Yerba Mate naturally contains caffeine, which is why it has a stimulating, energizing effect similar to coffee or tea.
Can Yerba Mate help me lose weight?
Some early studies hint at possible effects on weight and metabolism, but the evidence is limited and not convincing. It is not a proven weight-loss treatment.
Is it safe to drink Yerba Mate every day?
Moderate daily use is acceptable for many healthy adults, but drinking it very hot and in large amounts over many years has been linked to higher risk of throat and esophageal cancer, so enjoy it warm and in moderation.
Can I drink Yerba Mate while pregnant or breastfeeding?
It is best to be cautious. Because mate contains caffeine that can reach the baby, limit or avoid it during pregnancy and breastfeeding and check with your doctor first.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Products that contain Yerba Mate

A rotating sample of real supplements in our database that list Yerba Mate — open any to see its full ingredients and every drug interaction we check.

See all 68 products with Yerba Mate →
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