Promotes Circulatory Health High Potency 2,000 FU's of Activity Vegetarian FormulaNattokinase is an enzyme isolated from Natto, a traditional Japanese fermented soy food. Natto has ben consumed safely for thousands of years for its numerous health benefits. More recently, both clinical and non-clinical studies have demonstrated that Nattokinase supports heart health and promotes healthy circulation. Each serving of NOW Nattokinase provides 2000 FU (Fibrinolytic Units) to help keep already healthy levels of blood clotting factors within a normal range.