Yerba mate is a traditional South American brew that’s been said to offer the “strength of coffee, the health benefits of tea, and the euphoria of chocolate” all in one beverage

It was called “the drink of the gods” by many indigenous South Americans and later “the green gold of the Indios” by European settlers.

You may have come across the claim that yerba mate contains no caffeine, but this is not true. 
 

It contains 85 mg of caffeine per 8-ounce cup, which is more than tea but less than coffee. You may hear that yerba mate contains mateine instead of caffeine.

While the caffeine-like effect of yerba mate may feel different than that of coffee, a unique compound has not yet been discovered. 

One theory is that mateine is probably just caffeine bound to a tannin or phenol in the raw leaf.

https://bebrainfit.com/yerba-mate-benefits/