Milk Thistle (Silybum marianum) has been used by traditional herbalists for centuries. Clinical and non-clinical studies have indicated that milk thistle extract may help maintain healthy liver function through its ability to promote glutathione production, as well as by supporting the body's normal detoxification processes.* NOW® Extra Strength Milk Thistle has five times the milk thistle extract (750 mg per capsule) as in our regular strength product (150 mg per capsule). Natural color variation may occur in this product.