Yerba mate contains an abundance of bioactive compounds that could act both independently and synergistically to produce various biological effects. However, most mechanisms are theoretical, and more research is needed to better understand how yerba mate works.
Yerba mate's stimulant properties are mostly attributed to its caffeine content. On average, the content of caffeine in yerba mate is less than coffee, but it can be similar depending on brewing conditions.[1][2]
The xanthines in yerba mate (e.g., caffeine, theophylline, and theobromine) are also suggested to be responsible for increasing fat oxidation and thermogenesis.[3] This, combined with the regulation of genes involved in adipogenesis (the synthesis of new fat cells) and the increased production of glucagon-like peptide 1 (GLP-1), could contribute to the proposed antiobesity effect of yerba mate.[4][5] Despite this, clinical trials have generally reported negligible weight loss effects.[6][7][8]
Yerba mate is rich in polyphenols, such as chlorogenic acid and caffeic acid, that have antioxidant activity and may help protect the body from oxidative stress. These compounds can directly scavenge free radicals while also enhancing the body’s own antioxidant defense mechanisms.[2]
The lipid-lowering effects of yerba mate have been proposed to be due to the reduced absorption of fats[9] and the regulation of lipid metabolism.[10] Theoretically, yerba mate might also reduce glucose absorption[11] and enhance glucose uptake by cells in the body, providing a blood-glucose-lowering effect.[12][13] Increased levels of GLP-1 may further support blood glucose regulation.[5]