Extracted from the seeds of the herb milk thistle, silymarin has been used for centuries to treat liver disease.  The active ingredients in milk thistle are several types of flavonoids (powerful antioxidants), known collectively as silymarin.

Silymarin guards the liver from oxidative damage.  It also protects the liver from toxins, drugs, and the effects of alcohol, and promotes the growth of new liver cells.  In addition, silymarin increases levels of glutathione, superoxide dismutase, and catalase, potent antioxidant enzymes that protect the liver.  It has also been shown to reduce insulin resistance, which may help patients with diabetes.