Natto-K is a tried and tested formula that supports cardiovascular health by helping the body?s natural circulation processes . The key ingredient is Nattokinase with NSK-SD?the only form of nattokinase that does not contain vitamin K2?which assists in the body?s natural production of plasmin. As plasmin breaks down excess fibrin this has been shown to improve circulation help maintain normal levels of blood clotting factors and promote optimal circulation.