Last year I started taking Osteo Bi-Flex (over the counter in the vitamins) and I couldn't believe the difference in about 10 days! Both of my knees are bone on bone and I was barely able to walk. The surgeon said I was too young to have the replacement and wouldn't give me cortisone shots because they supposedly raise your glucose and I am a diabetic. I take one tablet twice a day and I haven't had much problems since I started these. They are a miracle! I've had problems since I was 18 and I'm 55 now (it sure doesn't seem too young!).