Yerba Mate (Ilex paraguariensis)

Yerba mate is a South American herbal tea that naturally contains caffeine and is traditionally drunk from a gourd. Most people drink it the way they would coffee or tea. The one human trial cited here looked at body fat over 12 weeks, not energy, focus, or antioxidant status, so treat the alertness part as ordinary caffeine rather than something proven for mate specifically.

Yerba mate contains caffeine, generally less than coffee but more than most teas (roughly 30 to 80 mg per cup), along with other compounds that some feel give a smoother, less jittery energy. Count it toward your daily caffeine.

People mainly drink it as a caffeinated beverage. The only human trial cited on this page gave 3 g a day of mate capsules for 12 weeks to 30 adults with obesity and found a small reduction in body fat; no cited study measured energy, focus, or antioxidant markers. It remains a staple social drink in South America.

In moderate amounts it is generally well tolerated. Two cautions. First, it contains caffeine, so the usual caffeine limits apply, especially during pregnancy, if you are sensitive to stimulants, or if you take other stimulants. Second, the cancer concern is about temperature rather than the plant: drinking any beverage above about 65 C (150 F) is classified as probably carcinogenic, and traditional mate drunk scalding hot is linked to esophageal cancer, while mate at ordinary temperatures was not classifiable as to carcinogenicity. Let it cool before you drink it.

Yerba mate is the dried leaves of a South American holly tree — traditionally consumed as a beverage in Argentina, Paraguay, Uruguay, and Brazil. Contains caffeine, theobromine, and rich polyphenols (chlorogenic acids, saponins, flavonoids).

The clinically studied dose is The only cited trial used 3 g a day of yerba mate capsules for 12 weeks. Supplements sold at 500 to 2,000 mg a day are below the amount that was tested, so the trial result may not carry over to them. Always follow the product label and check with a healthcare provider for personal advice.

For most healthy adults, Yerba Mate is well tolerated at studied doses. Reported effects can include: Caffeine-related: insomnia, anxiety, jitteriness, palpitations. GI distress. It may also interact with some medications. Yerba Mate is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Possible interactions include: Caffeine-sensitive medications (theophylline, theobromine) — additive effects. Stimulants (amphetamines, ephedra) — additive cardiovascular effects. If you take prescription medication, check with a pharmacist or doctor before using it.

NutraSmarts rates the evidence for Yerba Mate as Limited (2 out of 5). It is backed by 2 clinical trials and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.