search for a product called Rutozyme made by Naturally Vitamins in Scottsdale, AZ. It is amazing -- made from an extract of natto miso from Japan; well researched and proven to help prevent any clotting. I would try it along with what else you are taking ... find the research and you'll be pleased. I take 3 tabs x 2 daily and trust it 100% even when I am flying long 14 hour flights. Good luck.