It is true that silymarin has been identified as the active component in milk thistle responsible for promoting liver health.* Silymarin also has important antioxidant properties.* Yet silymarin only makes up about 1.5-3% of the dry weight of the small, seed-like milk thistle fruits.1 The rest of these fruits are composed of proteins, fatty acids, sugars, and other phytonutrients with beneficial properties. Puritan’s Pride offers both standardized and non-standardized milk thistle extracts. A standardized milk thistle extract will provide a set amount of silymarin whereas an unstandardized extract will provide the goodness of the whole herb.