Dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) are two closely related chemical compounds that have been explored for their potential to help with osteoarthritis. DMSO is generally applied to the skin, whereas MSM is available as a dietary supplement, often included with other elements such as glucosamine. Bottom Line Very limited studies have been done on the effectiveness of DMSO and MSM for easing symptoms of osteoarthritis. As a result, it's not clear whether these