Nattokinase supports cardiovascular wellness and healthy circulation. If you've never heard of Natto, you're not alone. A staple of the Japanese diet for ages, this fermented soybean dish has remained relatively unknown in the West. The fermentation process produces the unique enzyme Nattokinase. Evidence suggests that Nattokinase may be an effective dietary approach for supporting healthy blood flow, thereby promoting circulatory and cardiovascular health. Nattokinase activity is measured by the number of "fibrinolytic units" (FU). Swanson Ultra Nattokinase is guaranteed to deliver 2,000 FU per capsule.