HELPS SUPPORT CARDIOVASCULAR SYSTEM HEALTH Alive Vitamins™ Nattokinase Fermented Enzyme from Japanese Natto Beans Nattokinase is an enzyme extracted from soybeans scientifically studied on its potent fibrinolytic (clot-busting) activity. This results in breaking down fibrinogen, a component of blood clots and atherosclerotic plaque. Elevated fibrinogen levels are another clear risk factor for cardiovascular disease. Nattokinase also improves varicose veins, improves blood circulation, and relieves nasal inflammation.