Silymarin is the main active ingredient of the fruit of the plant Silybum marianum (commonly known as milk thistle) , an herb native mainly to the Mediterranean. Silymarin consists of 3 individual isomers called Silybin, Silidanin and Silicristin, substances that belong to the flavonolignans, a powerful group of plant active ingredients and Silybin is considered the most powerful of the three. Milk Thistle is one of the herbs with the most references in the scientific literature as there are over 300 publications in the international literature on its chemical composition and mechanisms of action.