The Glucosamine / Chondroitin Arthritis Intervention Trial (GAIT), a randomized, double-blinded, placebo-controlled, multicenter clinical trial of 1583 patients with symptomatic osteoarthritis of the knee, reported that, alone and in combination with chondroitin sulfate (400 mg 3 times a day), glucosamine hydrochloride (500 mg 3 times a day) did not reduce pain effectively in the all-patient group.