Glucosamine, Chondroitin Sulfate

Glucosamine and chondroitin sulfate are produced in the human body and are involved in the production and maintenance of cartilage that cushions joints. The supplement glucosamine is manufactured from shellfish shells; chondroitin, usually from cow bone. Millions of Americans with osteoarthritis take glucosamine, often with chondroitin sulfate. Many experts hope that supplemental doses may indeed slow or prevent deterioration of cartilage and thus reduce the pain and stiffness of arthritis.

Claims, purported benefits: Cures or alleviates arthritis pain; helps build cartilage and cushion the joints; prevents deterioration of cartilage.

Bottom line: Research has yielded conflicting findings about their effectiveness. In 2006 a large, well-designed government-sponsored study of people with osteoarthritis of the knee found that neither glucosamine nor chondroitin, alone or in combination, worked significantly better than a placebo in reducing pain or other symptoms. In a 2008 follow-up study, subjects continued treatment for an additional 18 months and then had X-ray exams to measure cartilage loss. The exams found only insignificant differences in cartilage loss between the groups. Glucosamine and chondroitin actually did worse when taken together than alone, but nothing worked much better than the placebo. The researchers ended with several caveats and questions and called for still more research. But this was a large, expensive, well-designed study, and it’s hard to imagine that a better one will be done any time soon.

We suggest you forget about glucosamine and chondroitin—unless you’re willing to pay $20 or $30 or more a month for what is probably a placebo effect. If you already take these supplements and find they help, continue with them, but consider stopping for a while to see if there’s a difference.