Based on personal experience, I am convinced that Metanx acts as a blood thinner, at least for me. It delays coagulation to where a slight cut bleeds profusely. I had a small sty removed from my eyelid and it took considerable time for the surgeon to get the bleeding stopped. The nurses wondered if I was taking a herb of some sort. Some time later, I cut my finger, same result. When I stop Metanx, no problem.