According to WebMD, there is not enough clinical research to substantiate claims of milk thistle benefits. Silymarin is the primary active ingredient in milk thistle, and it has been established as an antioxidant and anti-inflammatory, but silymarin's actual benefits are unclear.
According to WebMD, milk thistle is used by some people as a treatment for liver problems, including jaundice, hepatitis, gallbladder disorders and cirrhosis. Other claims of milk thistle benefits include heart benefits from lowering cholesterol, improving the symptoms of type 2 diabetes and minimizing the growth of cancer cells in cervical, prostrate and breast cancers.
Milk thistle may be consumed orally in supplements or teas and may be taken in conjunction with other herbs, according to WebMD. There are few side effects from taking milk thistle.