Yeah, my wife takes that stuff too, (Glucosamine Chondroitin Complex supplement). It helped her for awhile, then one of her knees started bothering her. Got recommended to a sports medicine doc, who noticed right away that she has one leg longer than another! So, been seeing a physical therapist who's getting her all "staightened out" (can't believe they didn't recommend a Chiropractor).
But she still takes the supplements too, I also heard this "shark cartilage" stuff is good for joint problems.

Gilly