A large, well-designed study published in the New England Journal of Medicine examined whether glucosamine and chondroitin could reduce knee pain from osteoarthritis. The study—known as the Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT)—included 1,583 participants and used a double-blind, placebo-controlled design.
Participants were randomly assigned to receive one of five treatments for 24 weeks: celecoxib (Celebrex), glucosamine hydrochloride, chondroitin sulfate, a combination of glucosamine and chondroitin, or a placebo. A successful outcome was defined as at least a 20% reduction in knee pain from baseline.
In the overall study population, the glucosamine–chondroitin combination performed only slightly better than placebo. About 60.1% of participants in the placebo group achieved a 20% pain reduction, compared with 66.6% of those taking the supplement combination. Celecoxib showed the strongest overall effect, with 70.1% of participants reporting improvement.
However, results differed in participants with moderate to severe knee pain. In this subgroup, 79.2% of those taking the glucosamine–chondroitin combination experienced significant pain relief, suggesting that the supplements may be more helpful for individuals with more advanced symptoms.
