Natto kinase is an enzyme derived from natto, a traditional Japanese food made from fermented soybeans. It is produced by the bacterium Bacillus subtilis during the fermentation process. Natto kinase is known for its ability to break down fibrin, a protein involved in blood clotting, which may help improve circulation and reduce the risk of blood clots. Research suggests that natto kinase may have various health benefits, including supporting cardiovascular health and promoting overall wellness. It is available as a dietary supplement and is often marketed for its potential to enhance blood flow and reduce the risk of certain health conditions related to blood clots.