In preliminary open-label human clinical trials totaling 37 subjects with OA, oral supplementation with 500 mg per day of NEM® resulted in an observed decrease in pain in 7-30 days. Therefore, an eight week randomized, multicenter, double blind, placebo controlled supplementation trial was conducted to evaluate the efficacy and safety of NEM® for the relief of the pain and stiffness associated with moderate OA of the knee - the Osteoarthritis Pain Treatment IncorpOrating NEM® (OPTION) trial.