A review of two small randomized controlled trials of methylsulfonylmethane in osteoarthritis (OA) knee pain relief "reported significant improvement in pain outcomes in the treatment group compared to comparator treatments; however, methodological issues and concerns over optimal dosage and treatment period were highlighted." The two trials included 168 people, of whom 52 received MSM, either 1.5 g/day or 6.0 g/day. The review authors stated: "No definitive conclusion can currently be drawn" and there is "no definitive evidence that MSM is superior to placebo in the treatment of mild to moderate osteoarthritis of the knee."