Science & Fun - Jonathan Graehl

An analysis of 10 studies involving more than 3,800 people has found that glucosamine and chondroitin supplements for joint pain are ineffective either alone or in combination.

(no change in pain or actual joint condition)

I had been taking this for mild lower back and knee pain. I never noticed any benefit but trusted in the earlier research which said it definitely relieved pain. Pure placebo, it turns out.