Hilde Hemmes Herbal's St. Mary's Thistle 1000mg 120vcSt Mary's thistle is the most extensively studied liver remedies in western herbal medicine. Not only has the active constituent (silymarin) been well studied but the product itself has been involved in countless, successful clinical trials. Its primary role is to protect the liver against potentially harmful chemicals, especially alcohol. Studies have shown that it supports the regeneration and detoxification of the liver and normal liver function.