I Have a slightly different answer then everyone else..although my review is also good, i found that I bought the cheap stuff first, and it wasn't the chondritin, just Gloc. I was suprised within 2 weeks I was feeling shoulder and knee pain reduced almost to nil. The knee pain was repetitive locking and snapping, the shoulder is heavy lifting strain...so 2 differnt types of aches, both improved in a short period of time.
I also heard/read that you need to take it forever. I hate taking anything, including advil...so i was quick to see if it was temp pain relief, or what. I found after about 2 months, and feeling great, i stopped for 2 weeks and still felt fine....i continued without for about 1 more month, and noticed 1 day of aches. I waited about 3 more weeks, then started to get some soreness again.
I started back with only taking it on "push" days at the gym (3 days a week). I stayed on that for about 1 year with no aches and pains in knees or shoulders. I have been off since June and only had 1 day where it was aching. (ps..this time it is the chondritin/glocousimin).
I agree with everyone that it works..I just think you can experiment with cheap up to expensive stuff, and find out regularity of your needs....I Highly recommend everyone that thinks it might help, to try it.
wish you luck!
bb