I tried this product at on the advice of a physician as he had used it and was pleased with the result. My knee pain was intermittent and related to exercise on hard surfaces and I have no underlying joint issues. My knee quit hurting within two weeks and I continued pain free after the first bottle ran out and I was using only a half dose per day. After being off for two months I bought more product as it did not seem wise to tempt fate. Be aware the product does contain magnesium so check other supplements you take to avoid any side effects of hi dosages of magnesium.
I have been using this for several years and it works better than any other pain killer I've used.