Standardized Silymarin Extract 30:1. Supports Liver Function. Gluten Free. Jarrow FORMULAS® Milk Thistle (Silybum marianum) 30:1 concentrate is standardized to contain 80% total Milk Thistle seed flavonoids including the important Silymarin fractions isosilybinins A and B silybinins A and B silychristin and silydianin. This particular group of flavonoids collectively known as Silymarin support liver function by raising protective glutathione levels.