Traditionally, it has been used as a stimulant and for the treatment of arthritis, difficult digestion, liver diseases, headache, rheumatism and obesity. Yerba mate is rich in polyphenols such as caffeine, caffeic acid, catechin, epicatechin gallate and quercetin. These polyphenols have antioxidant activity, the ability to scavenge oxidative stress causing free radicals. Mate has shown to have a relaxing effect on smooth muscle tissue, and a stimulating effect on myocardial (heart) tissue. It also contains elements such as potassium, magnesium and manganese. Tea made from mate has been shown to lessen the tendency of obesity induced by a high-starch diet.

Yerba mate, also known as erva-mate in Portuguese, originates from South America and is extracted from the dried leaves of Ilex paraguariensis.

Some people also take yerba mate by mouth to improve mood and depression; for diabetes; high cholesterol; weak bones (osteoporosis); to relieve headache and joint pains; to treat urinary tract infections (UTIs), and bladder and kidney stones; for weight loss; and as a laxative.