As of 2015 the largest trial conducted with the product was the Glucosamine and Chondroitin Arthritis Intervention Trial (GAIT), a double-blind, randomized, multicenter clinical trial sponsored by the US National Institutes of Health in 1583 people with knee osteoarthritis, which was published in the New England Journal of Medicine in 2006. Subjects were randomly assigned to one of five orally administered treatments: two 250 mg capsules of glucosamine hydrochloride three times daily, two 200 mg capsules of chondroitin sulphate three times daily, two capsules of 250 mg of glucosamine hydrochloride plus 200 mg of chondroitin sulphate three times daily, 200 mg of celecoxib daily, or placebo. Treatment was administered for 24 weeks. It showed no difference from placebo.