This is one great supplement I must say. I have had a knee problem ever since it went out on me when I was playing tennis many years ago. I started taking this supplement about one year ago and I have to say it has helped me quite a bit. I am pretty active as I go to the gym several times per week and also hike as well. These supplements contain glucosamine hydrochloride, chondroitin sulfate, uniflex proprietary extract and hyaluronic acid. I have to say I cannot believe the results that I have attained. My knee does not bother me anymore. When you first start the supplements you take 2 tablets twice per day for two weeks. Then you take 2 tablets once per day after that to maintain. I am very surprised at the effectiveness of these supplements. I want to remain active and these make that possible. I have other friends that have tried them as well and they also report good results. I keep them on my office desk along with my vitamin supplements that I take each day. This is one very effective product.