The role of glucosamine and chondroitin sulfate in osteoarthritis
June 01, 2000 – Article #3097
University of Maryland researchers evaluated over-the-counter glucosamine and chondroitin products. Results showed major inconsistencies—some contained 0% of what was claimed, others more than 115%.
Of 14 glucosamine and 11 chondroitin products tested, many failed label claims. Products under $1 per 1,200mg of chondroitin sulfate often contained less than 10% of the labeled amount.
They also evaluated how well these products were absorbed. Lower molecular weight chondroitin sulfate showed higher absorption potential—suggesting it may be more effective.
Consumer advice: Buy from trusted vendors, ideally using USP-grade ingredients. Regulatory oversight is needed to protect quality and accuracy in labeling.
Glucosamine & Methylprednisolone Interaction Study
Byron CR, Benson BM, Stewart AA, Pondenis HC – University of Illinois
This in vitro study found that methylprednisolone reduced proteoglycan production in equine chondrocytes. However, glucosamine protected that production across all concentrations tested.
Conclusion: Glucosamine may be a valuable adjunct treatment alongside corticosteroid joint injections.
Research Ongoing: Glucosamine Sulfate vs. Hydrochloride
By Stacey Oke, DVM, MSc – March 26, 2008, Article #11549
Canadian researchers compared oral glucosamine sulfate and hydrochloride. Horses given sulfate showed significantly higher glucosamine levels in their synovial fluid at 1 and 6 hours post-dosing.
The sulfate used was enhanced with palatability agents, possibly improving absorption. More studies are needed to confirm long-term clinical impact on osteoarthritis.
This study will appear in Osteoarthritis and Cartilage.