Dietary Supplement Silybum Marianum 80% Silymarin 350 mg Per Capsule Guaranteed Potency Lab Verified Non-GMO 100% Vegan Discussion: Native to the Mediterranean region, milk thistle has been used medicinally for over 3,000 years. Milk thistle is considered to be one of the best liver tonics in the world. Milk thistle seed extract is intended to provide nutritive support for a normal, healthy liver.