What Is Yerba Mate? | The Caffeinated South American Infusion

Yerba mate is a traditional South American infusion made from the leaves of the Ilex paraguariensis tree, prized for its caffeine-based stimulant effects.

If you’ve seen the gourd-and-metal-straw setup at a café or spotted the canned versions in a cooler, you’ve met yerba mate. It’s a caffeinated herbal drink that functions the way coffee or tea does for millions of people — except it comes from a South American tree most Americans have never heard of until recently. The question of what yerba mate is comes down to one plant, one traditional preparation, and a handful of effects that explain why it’s spread far beyond its home region.

Where Yerba Mate Comes From

Yerba mate is made from the dried leaves and stems of Ilex paraguariensis, an evergreen tree native to the subtropical forests of South America. The leaves are harvested, dried, and often aged before they’re steeped in hot water.

In Argentina, Paraguay, Uruguay, and southern Brazil, drinking mate is a daily ritual. The traditional setup involves a hollow gourd (the calabaza), a metal straw with a filter at the bottom (the bombilla), and loose yerba leaves packed into the gourd. Hot water is poured over the leaves and sipped through the straw, and the same leaves are refreshed with more water throughout the session.

That’s the traditional route. In the United States, most people encounter yerba mate in a different form: bottled or canned ready-to-drink beverages, tea bags, or loose leaf sold at grocery stores and online. It has also become a common ingredient in dietary supplements, often blended with other botanicals for energy-focused formulas.

Why People Drink It: Effects And Caffeine Content

Yerba mate is consumed primarily for its stimulant effect. It contains caffeine, which is why it delivers an alertness boost similar to coffee or tea — though the experience tends to differ. Many regular drinkers describe mate’s energy as smoother than coffee’s, with less of a jittery spike and crash.

Beyond energy, yerba mate has been studied for a range of possible health effects. The reality is that while some studies show promise, stronger evidence is still needed for most of these claims. It’s a caffeine-containing beverage with some interesting bioactive compounds, not a medicine.

The safety picture for most adults is fairly reassuring. Mayo Clinic reports that drinking yerba mate is not associated with health problems in most adults, and notes that a daily cup prepared with 3 grams of leaves may be safe for up to 12 weeks. That said, the caffeine in mate brings familiar side effects for some people: upset stomach, trouble sleeping, nervousness or restlessness, a fast heartbeat, headaches, and palpitations.

What To Know About Safety And Risks

Yerba mate is not risk-free, and the caveats matter for heavy users. The main concern involves long-term, high-volume consumption. Some studies have linked heavy, long-term yerba mate intake with a higher risk of cancers of the mouth, throat, lungs, and other head-and-neck sites. The risk appears higher in people who also smoke or drink alcohol regularly.

There’s also a temperature angle. Some research suggests the risk may be higher with very hot consumption, a pattern also seen with other piping-hot beverages like coffee and tea. The strongest and most consistent risk signal in the medical literature, though, is tied to heavy, long-term intake rather than occasional use.

Two other groups should check with a health care provider before drinking yerba mate. Pregnant people are advised to consult a professional because of the caffeine content. And while rare, cases of clinically apparent liver injury have been linked to yerba mate, according to NCBI LiverTox, despite its generally safe reputation and widespread use.

If you’re ready to try it, a quality loose-leaf product is the best starting point. Our roundup of the top Argentina-sourced yerba mate brands breaks down the options worth buying.

Is Yerba Mate Legal And Regulated In The United States?

Yes. Yerba mate is legally sold in the United States as a beverage and as a dietary supplement ingredient. It’s widely available in supermarkets, health food stores, and online retailers.

The regulatory caveat is narrower: NCBI LiverTox notes that yerba mate is not approved in the United States as therapy for any disease or condition. That’s a meaningful distinction. It’s legal to sell and drink as a food or supplement, but the FDA has not evaluated it as a treatment, and no one should approach it that way.