Milk thistle has been used by the traditional health practitioners of Europe since the Middle Ages. Available in superior extended release, Nature's Plus Herbal Actives Milk Thistle seed extract is uniformly standardized to a minimum of 80% (400 mg) silymarin to guarantee that each and every tablet provides consistent potency and activity. Each tablet, providing the greatest concentration of active botanical principles, maximizes the synergistic benefits of the whole seed, which naturally contains silybin, silydianin and silychristin.