Glucosamine and chondroitin, used separately or together, are among the more popular diet supplements. They are used widely for osteoarthritis, especially of the knee, and have been better studied than most other diet supplements. But do they really work?
The journal of my medical specialty, American Family Physician, recently published an article about the use of dietary supplements in osteoarthritis. They gave a “B” evidence rating to both glucosamine and chondroitin. This means there is inconsistent or limited-quality patient-oriented evidence. They recommended the use of glucosamine sulfate, saying, “Overall, the evidence supports the use of glucosamine sulfate for modestly reducing osteoarthritis symptoms and possibly slowing disease progression.” They did not exactly recommend chondroitin, although they said it “may provide modest benefit for some patients.”