Prairie Doctor Milk Thistle - Has been used for thousands of years as a digestive aid, but it is most well-known as a superior herb for liver and gallbladder disorders. Milk thistle's effectiveness for all sorts of liver disorders is being confirmed today through laboratory studies and extensive clinical trials. The active ingredients in milk thistle are flavonoids comprised of silybin, silydianin and silychristin, collectively known as silymarin. Milk Thistle Extract is indicated for liver disease associated with alcohol abuse, chronic hepatitis, and protects those working with toxic chemicals and other substances harmful to the liver.