Glucosamine is a supplement that is often combined with another supplement, chondroitin to help the pain of osteoarthritis. Glucosamine is made from crab shells and chondroitin, from cow trachea. There is evidence in the literature that glucosamine alone and combined with chondroitin can help the pain of osteoarthritis.
Whether or not either slows down the damage to joint cartilage is less clear. The typical initial dose is 1500 mg of glucosamine and 1200 of chondroitin daily for 1- 2 months. If a response is obtained, the dose can be reduced to 1000 mg of glucosamine and 800 of chondroitin or less.
Because these supplements are not regulated by the FDA and the amount of active ingredient cannot be verified, I typically recommend my patients use one of the "brand name" products such as Cosamin DS (glucosamine plus chondroitin) or DONA (glucosamine)for at least 2 months before switching to a less expensive product. As pointed out in Tufts study, whether higher doses might be more effective without increased toxicity is unclear.
Glucosamine should be avoided in patients who are allergic to shellfish and some reports suggest elevation of blood sugar in diabetics. Finally, patients on the blood thinner coumadin may have an increased risk of bleeding.
Answer provided by Scott J. Zashin, M.D., clinical assistant professor at University of Texas Southwestern Medical School, Division of Rheumatology, in Dallas, Texas. Dr. Zashin is also an attending physician at Presbyterian Hospitals of Dallas and Plano. He is a fellow of the American College of Physicians and the American College of Rheumatology and a member of the American Medical Association. Dr. Zashin is author of Arthritis Without Pain - The Miracle Of Anti-TNF Blockers. The book is a must-have for anyone on one of the biologic drugs (Enbrel, Remicade, Humira) or considering the biologic drugs. Read my review of the book.