Blueberry Naturals Milk Thistle Extract Plus 175mg Capsules is best known for its content of Silymarin. Milk thistle is a herbal remedy derived from the milk thistle plant, also known as Silybum marianum. The active ingredients in milk thistle are a group of plant compounds collectively known as silymarin. The silymarin extracted from milk thistle is known to have liver-protecting effects. This formula contain 175 mg Milk thistle extract standardized to 80% (140 mg) silymarin.