Nattokinase is a specialized fibrinolytic enzyme for support of healthy circulation.^◆ The Japanese food natto (from which nattokinase is extracted) is very rich in vitamin K2 which, although it is an excellent form of vitamin K, is contraindicated with many medications prescribed to prevent blood clots. While many supplements may also contain some vitamin K, the nattokinase used in NATTO NSK MEGA™ (Nattokinase NSK-SD™) is produced under a specific patented process that removes all the vitamin K, yielding only the purified enzyme.^◆