Nature's velvet milk thistle contains silymarin and vitamins of the b-complex group. Milk thistle is a powerful and safe herb. It has been used traditionally for thousands of years. The active ingredient in milk thistle is called silymarin. Milk thistle is also known as mary thistle or holy thistle. The silymarin extracted from milk thistle is known to have antioxidant property. Milk thistle extract has a high amount of silymarin (80%) that has been concentrated from the milk thistle plant.