I am no expert, but I have done some research on these. My father was to be put on Warfarin/Coumadin, and I did not like that one bit. Nattokinase acts like warfarin... it thins the blood as well as stops plaque from building up on the atreries. Serrapeptase disolves what has already built up.... so you can use both... one to disolve old deposits, one to stop more from adhereing.