I used to take the same supplements, for years, actually. Then, one day, I realized that I was still having the same arthritis pain, and the pills really didn't do that much for me. I THOUGHT they did, but hubby pointed out that I complained of knee pain just as much as I ever did. Then my doctor's office sent out a newsletter that mentioned studies showed Glucosamine and Chondroitin just don't work any better than a placebo.
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On the other hand, it doesn't seem to have any side effects, unless you are diabetic, so it can't hurt you. I guess if you think it works, then it will. YMMV.