Nattokinase is an enzyme derived from natto a traditional fermented soy food popular in Japan. During the natto production process non-GMO soybeans are boiled and fermented with friendly Bacillus subtilis bacteria producing nattokinase. Doctor?s Best Nattokinase contains nattokinase enzyme with Vitamin K2 removed. Nattokinase has been shown to support a healthy circulatory system by helping to maintain normal fibrinogen levels in blood.* At Doctor?s Best we lead with science. Our products are backed by research and crafted using pure ingredients carefully sourced from around the globe. Since 1990 we have dedicated ourselves to providing highly effective nutritional supplements that enable you to live a healthier lifestyle. We want nothing more than to see you and your family thrive!