Yerba Mate

Ilex paraguariensis · Mate tea

Snapshot

Indications	Contraindications
Glycemic control in prediabetes¹ Oxidative stress markers^{2, 3} Appetite suppression^{4, 5} Fatigue (traditional use)⁶ Minor urinary complaints (traditional)⁶	Hypertension⁶ Arrhythmia⁶ Gastric or duodenal ulcers⁶ Hyperthyroidism⁶ Pregnancy and lactation⁶

Yerba mate (Ilex paraguariensis) is a caffeinated South American leaf infusion containing methylxanthines, caffeoylquinic acids, and saponins⁷. Its stimulant effect, driven by the methylxanthines, underlies use for fatigue, where the European herbal monograph lists traditional use for fatigue and sensation of weakness⁶. Further uses are body weight and appetite, glycemic control, and lipid and cardiometabolic risk². Typical patients are adults with obesity, dyslipidemia, or prediabetes.

A systematic review found consistent effects on metabolism, antioxidant activity, and inflammation, with certainty of evidence ranging from moderate to very low². Another meta-analysis found no significant change in lipid levels⁸. A 2022 literature review of nutraceutical trials found contradictory glycemic results for Ilex paraguariensis, with rigorous long-term trials still lacking⁹. Products listing yerba mate number 768 in the label database, mostly tea bags, with capsules, tablets, and liquids; see Form comparison.

The most consequential caution is cardiovascular: the European monograph lists hypertension and arrhythmia as contraindications and notes that caffeine-containing preparations increase side effects of sympathomimetic medications⁶. Health Canada labels ask for a practitioner's advice before use with lithium¹⁰.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

44 sources, 32 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources