A traditional tonic, milk thistle has been long revered for its ability to promote detoxification and a healthy liver. Most milk thistle supplements are made from the leaves and seed of the milk thistle plant that grows in Europe and the United States. Milk thistle’s active components are a group of flavonoids called silymarin, of which silibin has the most biological activity. Herbalists recommend that milk thistle supplements deliver 70% to 80% silymarin. Swanson Health Products offers milk thistle supplements in our Premium, Superior Herbs and Ultra lines. Swanson Premium Milk Thistle is made with the whole seeds. The Swanson Premium brand has both capsule and liquid formulas. Swanson Superior Herbs Milk Thistle is standardized to deliver 80% silymarin. Swanson Ultra Siliphos Milk Thistle Phytosome is standardized to 29%-36% silibin.