DMSO, an industrial solvent, has been in use most recently in a pharmaceutically pure grade for its local anti-inflammatory action that reduces joint or soft tissue pain. It has been employed extensively by veterinarians and until recently when it was made illegal, has been available to the public for experimental use. There is a fair amount of experience and studies regarding the external use of DMSO for aches and pains from injury or arthritis. Results have been variable. DMSO may have some antioxidant effect, but this has not been shown clearly. Some government studies using DMSO both topically and intravenously for brain-injured patients have found it to be less toxic than was previously thought, though they have not shown it to be very helpful.

DMSO is easily absorbed through the skin and can be irritating to the eyes or may cause nausea or skin rash. It seems to be helpful for some arthritis symptoms but is definitely not curative. Although there are still some avid users, DMSO has fallen out of vogue and is probably best avoided.

A breakdown product of DMSO, methylsulfonyl methane (MSM), is a nontoxic, physiologically active sulfur compound that may possess some anti-inflammatory and antioxidant properties. Though more research is needed regarding its safety and actions, MSM has become available recently, and its future appears promising, possibly in treating problems such as arthritis or inhalant allergies