Nattokinase, a fibrinolytic enyzme isolated from Japanese natto, helps to maintain healthy activity of the body's natural clotting and fibrinolytic processes. In an animal study conducted by Biotechnology Research Laboratories and JCR Pharmaceuticals of Kobe, Japan, nattokinase promoted healthy blood flow. Furthermore, researchers from JCR Pharmaceuticals, Oklahoma State University and Miyazaki Medical College indicated that nattokinase supports healthy clotting function compared to placebo. In 1995, scientists at the Miyazaki Medical College and Kurashiki University in Japan demonstrated the potential for nattokinase to support blood vessel health in human subjects. This product is contraindicated for individuals with a history of bleeding tendency or with conditions associated with bleeding. Due to potential synergistic effects, concurrent use with anticoagulant and blood pressure medications should be closely supervised by a health professional.