Herbal Extract Standardized Maximum Strength Formula for Proper Support & Maintenance of Normal Liver Function Dietary Supplement 21st Century...for a Healthier Future 100% Vegetarian Formula Guaranteed Quality - Laboratory Tested 21st Century Milk Thistle Extract (Silybum marianum) is grown wild in Europe and America and has been used as a powerful health tonic for over 2000 years. Silymarin, the active complex found in Milk Thistle Extract, is a powerful antioxidant. 21st Century's standardized herbal extracts are thoroughly tested to assure high quality standards are met.