Yerba Mate
Also called Ilex paraguariensis, maté, chimarrão, tereré.
Best grade C across 7 graded outcomes Botanical Last checked
The short answer
From 17 sourcesYerba mate is a caffeine-containing infusion of Ilex paraguariensis leaves. Small trials link it to modest body-fat and metabolic changes, but a 2025 meta-analysis of 13 trials found no effect on lipids or BMI. IARC classes drinking any beverage above 65 °C as probably carcinogenic, and mate leaves carry polycyclic aromatic hydrocarbons. Caffeine limits apply.
Every graded outcome on this page
7 rows · line = participants- CGrade CBlood cholesterol and triglyceridesCholesteroln 926
- CGrade CAfter-meal glucose and HbA1c in prediabetesBlood sugarn 285
- CGrade CBlood viscosity and microcirculationCirculation markersn 142
- DGrade DCardiometabolic markers in men at risk (standardized extract)Metabolic markersn 34
- DGrade DBody fat in adults with obesityBody fatn 30
- DGrade DEndothelial function after a single servingVascular functionn 13
- ∅No effectBody mass indexWeightn 624
- 4 more graded outcomes, in the evidence chapter
Key facts
- What it is
- An infusion of dried Ilex paraguariensis leaves, traditionally drunk hot (chimarrão) or cold (tereré)710
- Caffeine
- Contains caffeine and theobromine. LiverTox: mate drinks typically have caffeine concentrations similar to tea and coffee. 11 ready-to-drink mate drinks supplied 31–70 mg of bioaccessible caffeine per serving in a simulated digestion test; cold tereré extracted about 2.5 times more methylxanthines than coarse-ground hot chimarrão141610
- 2025 meta-analysis
- 13 RCTs: possible glucose benefits in prediabetes (2 trials of a combination tablet, low certainty), but no effect on lipids, fasting glucose, waist or BMI (BMI: high certainty)6
- Cancer classification
- IARC (2016): drinking very hot beverages (above 65 °C) probably carcinogenic (Group 2A), based on oesophageal cancer; mate drunk not very hot is not classifiable (Group 3). Mate is traditionally drunk at about 70 °C7
- Contaminants
- Dry leaves of 8 brands held 536–2,906 ng/g of PAHs, including benzo[a]pyrene8
What it is
Yerba mate is a caffeinated South American infusion of Ilex paraguariensis leaves, also sold as capsules.
How it works
ProposedYerba mate supplies caffeine and theobromine, which account for its stimulant effects, plus chlorogenic acids (caffeoylquinic acids) proposed to drive metabolic effects. Antioxidant and anti-inflammatory actions are reported in reviews, but the certainty of evidence ranged from moderate to very low.1035
Forms, side by side
3 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.
Yerba Mate forms compared
3 forms| 3 forms | Traditional infusion (chimarrão hot, tereré cold) | Dried leaf capsules | Standardized extract (caffeoylquinic acids) |
|---|---|---|---|
| Absorption in people | Cold tereré extracted about 2.5 times more methylxanthines than coarse-ground hot chimarrão and almost all of the phenolics.10 | No head-to-head human data versus tea.1 | No head-to-head human data.3 |
| GI tolerance | Tolerability is not detailed in the tea-trial abstracts; drinking it very hot carries a cancer classification.27 | No clinically significant changes in safety measures over 12 weeks at 3 g/day.1 | Not detailed in the abstract.3 |
| Studied for | Circulation and acute vascular trials (5 g/day tea; single servings) | Body-fat trial (3 g/day for 12 weeks) | Cardiometabolic crossover trial (580 mg CQAs/day) |
- Traditional infusion (chimarrão hot, tereré cold)
- Absorption in people
- Cold tereré extracted about 2.5 times more methylxanthines than coarse-ground hot chimarrão and almost all of the phenolics.10
- GI tolerance
- Tolerability is not detailed in the tea-trial abstracts; drinking it very hot carries a cancer classification.27
- Studied for
- Circulation and acute vascular trials (5 g/day tea; single servings)
- Dried leaf capsules
- Standardized extract (caffeoylquinic acids)
What the human research says
Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.
Trial map
7 graded outcomes, largest study first7 graded outcomes: 3 improved, 4 no effect. The largest, a 2025 meta-analysis of 926 people on blood cholesterol and triglycerides, found no effect.
1Blood cholesterol and triglycerides
No effect · Grade C · Meta-analysis, 926 people, 2025
11 RCTs in healthy, overweight, dyslipidemic and HIV-positive adults
Dose, result and source| Outcome | Found | People | Study | Who was studied |
|---|---|---|---|---|
| Blood cholesterol and triglycerides | No effect | 926 | Grade C · Meta-analysis, 2025 | 11 RCTs in healthy, overweight, dyslipidemic and HIV-positive adults |
| Body mass index | No effect | 624 | No-effect grade · Meta-analysis, 2025 | 7 RCTs in healthy, overweight and dyslipidemic adults |
| After-meal glucose and HbA1c in prediabetes | Improved | 285 | Grade C · Meta-analysis, 2025 | 2 RCTs in adults with prediabetes (within a 13-trial review) |
| Blood viscosity and microcirculation | Improved | 142 | Grade C · RCT, 2015 | Adults with high blood viscosity |
| Cardiometabolic markers in men at risk (standardized extract) | No effect | 34 | Grade D · Crossover RCT, 2020 | Men aged 45–65 with at most one metabolic-syndrome criterion |
| Body fat in adults with obesity | Improved | 30 | Grade D · RCT, 2015 | Korean adults with obesity (BMI 25–35 and high waist-hip ratio) |
| Endothelial function after a single serving | No effect | 13 | Grade D · Crossover RCT, 2024 | Healthy adults aged 18–40 |
Every graded row
7 rowsShowing 7 of 7 outcomes. Human trials only.
CGrade CBlood cholesterol and triglyceridesCholesterolNo effectMeta-analysis · 11 studies
n 926 · 2025
No effect No significant effect on total cholesterol (MD -3.97; 95% CI -12.06 to 4.12), triglycerides, LDL or HDL cholesterol.
- Design
- Meta-analysis, 11 studies, n = 926, 2025
- Population
- 11 RCTs in healthy, overweight, dyslipidemic and HIV-positive adults
- Form
- yerba mate tea, capsules or tablets
- Dose
- 0.5 g/day of tablets up to tea brewed from 20 g of leaf a day
- Duration
- 5 days to 3 months
- Source
- Reference 6 · PubMed 41244043 (opens PubMed)
CGrade CAfter-meal glucose and HbA1c in prediabetesBlood sugarImprovedMeta-analysis · 2 studies
n 285 · 2025
Improved Post-meal glucose fell by 12.76 mg/dL (95% CI -16.78 to -8.74) and HbA1c by 0.37 points (95% CI -0.56 to -0.18) versus placebo; fasting glucose and fasting insulin did not change across trials.
- Design
- Meta-analysis, 2 studies, n = 285, 2025
- Population
- 2 RCTs in adults with prediabetes (within a 13-trial review)
- Form
- combination tablets of yerba mate extract with white mulberry and chromium picolinate (Glicoset)
- Dose
- 0.5 to 1 g/day
- Duration
- 3 months
- Source
- Reference 6 · PubMed 41244043 (opens PubMed)
CGrade CBlood viscosity and microcirculationCirculation markersImprovedRCT
n 142 · 2015
Improved Whole-blood and plasma viscosity fell and nailfold microcirculation improved versus placebo.
- Design
- RCT, n = 142, 2015
- Population
- Adults with high blood viscosity
- Form
- Yerba mate tea
- Dose
- 5 g/day
- Duration
- 6 weeks
- Source
- Reference 2 · PubMed 25562195 (opens PubMed)
DGrade DCardiometabolic markers in men at risk (standardized extract)Metabolic markersNo effectCrossover RCT
n 34 · 2020
No effect No significant treatment effect on blood pressure, glucose, lipids or inflammation versus placebo; within-group drops in fasting glucose and some subgroup changes were reported.
- Design
- Crossover RCT, n = 34, 2020
- Population
- Men aged 45–65 with at most one metabolic-syndrome criterion
- Form
- Encapsulated maté extract providing 580 mg caffeoylquinic acids/day
- Dose
- 580 mg caffeoylquinic acids/day
- Duration
- 4 weeks per period
- Source
- Reference 3 · PubMed 33374524 (opens PubMed)
DGrade DBody fat in adults with obesityBody fatImprovedRCT
n 30 · 2015
Improved Body fat mass, percent body fat and waist-hip ratio fell more than with placebo; no clinically significant safety changes.
- Design
- RCT, n = 30, 2015
- Population
- Korean adults with obesity (BMI 25–35 and high waist-hip ratio)
- Form
- Yerba mate capsules
- Dose
- 3 g/day (three capsules with each meal)
- Duration
- 12 weeks
- Source
- Reference 1 · PubMed 26408319 (opens PubMed)
DGrade DEndothelial function after a single servingVascular functionNo effectCrossover RCT
n 13 · 2024
No effect No acute effect on flow-mediated dilation, blood pressure, heart rate or heart-rate variability compared with water, whether hot or cold.
- Design
- Crossover RCT, n = 13, 2024
- Population
- Healthy adults aged 18–40
- Form
- Hot or cold yerba mate infusion
- Dose
- Single serving
- Duration
- Single dose (measured at 40 and 80 minutes)
- Source
- Reference 4 · PubMed 39708247 (opens PubMed)
∅No effectBody mass indexWeightNo effectMeta-analysis · 7 studies
n 624 · 2025
No effect No significant change in BMI (MD -0.17; 95% CI -0.36 to 0.02); waist circumference was also not significantly changed.
- Design
- Meta-analysis, 7 studies, n = 624, 2025
- Population
- 7 RCTs in healthy, overweight and dyslipidemic adults
- Form
- yerba mate tea, capsules or tablets
- Dose
- Varied across trials
- Duration
- Up to 3 months
- Source
- Reference 6 · PubMed 41244043 (opens PubMed)
What the numbers add up to
Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.
Hot vs cold
Small trials, mixed results
Studied doses
Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.
Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.
Doses studied in human trials
Doses studied in human trials ranged from 0.5 g/day of a yerba mate combination tablet for 3 months to 5 g/day of tea for 6 weeks, plus 3 g/day of capsules for 12 weeks and an extract providing 580 mg/day of caffeoylquinic acids for 4 weeks. Some tea trials brewed from 20 g of leaf a day. These are research doses, not recommendations.1236
Interactions and safety
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
What Yerba Mate meets
2 cited rows 1 tested togetherMedicines 1
Supplements and foods 2
- Measured in a human study
- Reference summary
- Tested together in a graded trial
Choose a medicine or supplement above to read its cited rows here.
Also cited: 1 tested together
Non-heme iron from meals
RCTMeasured in a human studyCan lower levels
Non-heme iron from meals, for example iron supplements and iron-rich plant foods (inferred): In 14 people with hereditary hemochromatosis, a mate infusion with a meal cut the rise in serum iron by about 88% compared with water.
Source 9, Food Funct (2021)
CaffeineCaffeine page
NIH fact sheetReference summary
Other caffeine sources, for example coffee, energy drinks, caffeine pills: Yerba mate adds caffeine to coffee, tea, energy drinks and pre-workouts; FDA says 400 mg/day of caffeine does not usually have dangerous effects in healthy adults.
Source 12, NIH Office of Dietary Supplements (2024); Source 11, Ther Drug Monit (2007)
Damiana leafDamiana leaf page
Tested together
Weight loss in overweight adults (yerba maté, guarana and damiana blend). Graded on the Damiana leaf page; tested together is not a claim that they work better together.
Interactions
2 agents| Agent | What the source says | Evidence |
|---|---|---|
| Medicines that can lower levels1 | ||
| Non-heme iron from mealse.g. iron supplements and iron-rich plant foods (inferred) | In 14 people with hereditary hemochromatosis, a mate infusion with a meal cut the rise in serum iron by about 88% compared with water.9 | RCT |
| Other supplements1 | ||
| Other caffeine sourcese.g. coffee, energy drinks, caffeine pills | Yerba mate adds caffeine to coffee, tea, energy drinks and pre-workouts; FDA says 400 mg/day of caffeine does not usually have dangerous effects in healthy adults.1211 | NIH fact sheet |
Check with what you take
Kept on this device onlyAdd what you take. We list every interaction our evidence profiles cite between Yerba Mate and your picks, and between your picks.
- Loading names…
Add a supplement or medicine you take to check it against Yerba Mate.
Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.
Who should be careful
5 groups- Pregnancy and breastfeeding
- EFSA set 200 mg/day of caffeine from all sources as the level not raising fetal safety concerns. A newborn whose mother drank homemade mate during pregnancy had withdrawal symptoms, with high caffeine and theobromine levels. LactMed notes that caffeine passes into breastmilk rapidly and names yerba mate among sources with similar dose-related effects on the breastfed infant; preterm and newborn infants clear caffeine very slowly.131115
- People who drink it very hot
- IARC classes drinking any beverage above 65 °C as probably carcinogenic (Group 2A), based on oesophageal cancer studies in places where tea or mate is drunk at about 70 °C; risk rose with drinking temperature. The classification names a hazard, not a level of risk. Mate that is not very hot is not classifiable (Group 3).7
- Caffeine-sensitive people
- Adverse events reported in mate trials included insomnia, tachycardia, headache and gastrointestinal discomfort.6
- Low iron stores
- Mate sharply reduced iron absorption from a meal in one trial, so regular use with meals may matter for people with low iron (inferred).9
- Liver
- LiverTox rates yerba mate D, a possible but rare cause of liver injury: a 21-year-old man developed acute hepatitis with jaundice after 4 months of daily mate and recovered within 2 months of stopping. Liver tests were normal in short clinical studies.14
Safety first
4 notesTemperature and contaminants matter as much as the leaf.
- Very hot drinks
- IARC found that risk of oesophageal cancer rose with the temperature at which tea or mate was drunk; mate is traditionally drunk at about 70 °C.7
- PAH exposure
- In 8 brands, total PAHs ranged from 536 to 2,906 ng/g of dry leaves, and hot and cold infusions both released them.8
- Caffeine
- Mate trials reported insomnia, tachycardia, angina, headache and gastrointestinal discomfort among adverse events.6
- Cold mate
- Cold mate had no carcinogenic effects in animal or human studies reviewed by IARC.7
How to read the label
What to check on the Supplement Facts panel.
How to read the label
3 checksFrequently asked questions
Short answers to common questions; the numbers link to the sources below.
Common questions
6 answersDoes yerba mate help with weight loss?
Does yerba mate have caffeine?
Yes, along with theobromine. LiverTox says mate drinks typically have caffeine concentrations similar to tea and coffee; 11 ready-to-drink mate drinks tested in 2023 supplied 31 to 70 mg of caffeine per serving that remained available after simulated digestion. Brewing matters: cold tereré extracted about 2.5 times more methylxanthines than hot coarse-ground chimarrão. In Argentina, mate was the main source of adults' 288 mg/day average caffeine intake.14161017
Does yerba mate affect iron?
In one trial it cut iron absorption from a meal by about 88% in people with hemochromatosis.9
Is yerba mate good for blood sugar?
Two small prediabetes trials suggest lower postprandial glucose and HbA1c, but fasting glucose was unchanged across trials.6
Does yerba mate cause cancer?
IARC (2016) classes drinking any beverage hotter than 65 °C as probably carcinogenic (Group 2A), based on oesophageal cancer in places where mate or tea is drunk at about 70 °C. Mate that is not very hot was not classifiable (Group 3). Mate leaves also carry polycyclic aromatic hydrocarbons, including benzo[a]pyrene.78
Is yerba mate safe in pregnancy and breastfeeding?
Count it as caffeine. EFSA set 200 mg/day of caffeine from all sources in pregnancy, and a newborn showed withdrawal after heavy maternal mate use. LactMed says caffeine reaches breastmilk quickly and lists yerba mate among sources with similar dose-related effects; newborn and preterm infants clear caffeine very slowly.131115
Sources
17 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.
Sources cited on this page
17 sources- 1Anti-obesity effects of Yerba Mate (Ilex Paraguariensis): a randomized, double-blind, placebo-controlled clinical trial.RCT BMC Complement Altern Med, 2015 · PMID 26408319
- 2Yerba mate (Ilex paraguariensis) improves microcirculation of volunteers with high blood viscosity: a randomized, double-blind, placebo-controlled trial.RCT Exp Gerontol, 2015 · PMID 25562195
- 3A Randomized Crossover Intervention Study on the Effect a Standardized Maté Extract (Ilex paraguariensis A. St.-Hil.) in Men Predisposed to Cardiovascular Risk.Crossover RCT Nutrients, 2020 · PMID 33374524
- 4The Acute Ingestion of Yerba Mate (Ilex paraguariensis) Infusion Does Not Modify Endothelial Function, Hemodynamics, or Heart Rate Variability: A Randomized Crossover Clinical Trial.Crossover RCT Plant Foods Hum Nutr, 2024 · PMID 39708247
- 5Physiological effects of yerba maté (Ilex paraguariensis): a systematic review.Systematic review Nutr Rev, 2023 · PMID 36647770
- 6Yerba Maté and its impact on glycemic control and metabolic health: a systematic review and meta-analysis.Meta-analysis Front Endocrinol (Lausanne), 2025 · PMID 41244043
- 7IARC Monographs evaluate drinking coffee, maté, and very hot beverages (Press release No. 244)Safety communication International Agency for Research on Cancer (WHO), 2016 · iarc.who.int
- 8High levels of carcinogenic polycyclic aromatic hydrocarbons in mate drinks.Observational Cancer Epidemiol Biomarkers Prev, 2008 · PMID 18483349
- 9Ilex paraguariensis (A. St.-Hil.) leaf infusion decreases iron absorption in patients with hereditary hemochromatosis: a randomized controlled crossover study.Crossover RCT Food Funct, 2021 · PMID 34173816
- 10Methylxanthines and phenolics content extracted during the consumption of mate (Ilex paraguariensis St. Hil) beverages.Observational J Agric Food Chem, 2010 · PMID 20058928
- 11Neonatal withdrawal syndrome after chronic maternal drinking of mate.Observational Ther Drug Monit, 2007 · PMID 17304161
- 12Dietary Supplements for Exercise and Athletic Performance: Fact Sheet for Health ProfessionalsFact sheet NIH Office of Dietary Supplements, 2024 · ods.od.nih.gov
- 13Scientific Opinion on the safety of caffeineGuideline EFSA Panel on Dietetic Products, Nutrition and Allergies (EFSA Journal 2015;13(5):4102), 2015 · doi.org
- 14Yerba MateDatabase LiverTox (NCBI Bookshelf), 2024 · ncbi.nlm.nih.gov
- 15CaffeineDatabase LactMed (NCBI Bookshelf), 2026 · ncbi.nlm.nih.gov
- 16Novel ICP-OES-Based Method for the Reliable Determination of the Total Content of 15 Elements in Yerba Mate Drinks along with the Determination of Caffeine and the In Vitro Bioaccessibility of the Compounds.Observational Molecules, 2023 · PMID 37110609
- 17Caffeine levels in beverages from Argentina's market: application to caffeine dietary intake assessment.Observational Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2009 · PMID 19680899
What changed
Every dated change to this page: what changed, who made it and why.
Change log
4 entries| Date | Change | Who and why |
|---|---|---|
| evidence, studied doses, key facts, summary, who should be careful, FAQ | A–Z audit. Added three graded rows from the 2025 meta-analysis of 13 trials (PMID 41244043, full text read for pooled numbers and certainty): after-meal glucose and HbA1c in prediabetes (C), blood lipids (C, no effect) and BMI (no effect, high certainty). Added caffeine content (PMID 37110609: 31 to 70 mg per serving in 11 drinks; PMID 19680899: mate the main caffeine source in Argentina) and LiverTox Yerba Mate (NBK610218, score D) to key facts, a liver note, and LactMed Caffeine (NBK501467, which names yerba mate) to the breastfeeding note. IARC press release No. 244 reopened; very-hot-beverage wording now matches it. Studied doses widened to 0.5 to 5 g/day. MedlinePlus no longer hosts a yerba mate page; no published drug interactions beyond caffeine and iron were found. Fact-checked against the sources; corrected: the two prediabetes trials tested a combination tablet (yerba mate with white mulberry and chromium), lipid and BMI trial lengths run to 3 months, the top tea dose is 20 g of leaf, and the 31 to 70 mg caffeine figure is from a simulated digestion test. | Writer: Kymata Health EditorialTrigger: A–Z page audit |
| all | Independent adversarial review: insight now lists the meta-analysis outcomes as reported (waist size, lipids, BMI), not body weight. | Writer: Kymata Health EditorialTrigger: review |
| all | Adversarial review pass: every evidence row, key fact, interaction, safety note and FAQ re-read against its PubMed abstract or source page, and every number machine-checked against the cited source text. Retraction, expression-of-concern and withdrawn checks on all PMIDs: none flagged. Fixes: meta-analysis outcomes matched to the abstract (waist and BMI, not weight); tea tolerability reworded; label-step title corrected. | Writer: Kymata Health EditorialTrigger: review |
| all | Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice. | Writer: Kymata Health EditorialTrigger: new page |
Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.