I had total reconstructive knee surgery in 1982. Since then my knee constantly hurt. Sometimes it was a dull ache and sometimes it was pure agony, but it always hurt. I was unable to participate in activities I enjoyed. I started taking Optimal Chronic a few weeks ago. The change has been phenomenal! I can walk a long way with little, if any, pain. I can enjoy physical activities again. I highly recommend Optimal Acute to anyone who suffers from long-term joint damage and pain.