DMSO has been used most widely as a topical analgesic, in a 70% DMSO, 30% water solution. Laboratory studies suggest that DMSO cuts pain by blocking peripheral nerve C fibers. Several clinical trials have demonstrated its effectiveness, although in one trial no benefit was found. Relief is reported to be almost immediate, lasting up to 6 hours. When administration ceases, so do the analgesic effects of the compound.

Chronic pain patients often have to apply the substance for 6 weeks before a change occurs, but many report relief to a degree they had not been able to obtain from any other source.

DMSO also reduces inflammation by several mechanisms. It is an antioxidant - a scavenger of the free radicals that gather at the site of injury. DMSO also stabilizes membranes and slows or stops leakage from injured cells and is recommended for many inflammatory conditions not caused by infection or tumor.

Stephen Edelson, MD, F.A.A.F.P., F.A.A.E.M., who practices medicine at the Environmental and Preventive Health Center of Atlanta, has used DMSO extensively for 4 years. "We use it intravenously as well as locally", he says. "We use it for all sorts of inflammatory conditions, from people with rheumatoid arthritis to people with chronic low back inflammatory-type symptoms, silicon immune toxicity syndromes and any kind of autoimmune process."

DMSO was the first NSAID discovered since aspirin. Some believe it was that discovery that spurred pharmaceutical companies on to the development on other varieties of NSAIDs. Pharmaceutical companies were thinking that if DMSO can have anti-inflammatory activity, so can other compounds, which are patentable. It is ironic that DMSO is less toxic and has fewer side-effects than any of them.

Some products contain DMSO as part of their formualtion. One such OTC topical product is called Soothanol X2.