I have had poor circulation my whole life, especially cold hands and feet, which got worse when I hit my 60s. I started on 1 capsule of nattokinase at dinnertime and rapidly felt more warmth in my hands. Then about a week later I had more warmth in my feet. This improvement to my extremities is remarkable to me because I have tried other supplements to improve circulation like horse chestnut but they absolutely did not help. I will continue to take 1 capsule of 2,000 a day. Only side effect is that I tend to bruise more easily but that's okay.