Dimethylsulfoxide (DMSO) is a chemical. It is available as a prescription medicine and also as a dietary supplement. It can be taken by mouth, applied to the skin (used topically), or injected into the veins (used intravenously or by IV).

DMSO is used for bladderinflammation (interstitial cystitis), limb pain that usually occurs after an injury (complex regional pain syndrome), and leakage of intravenous (IV) drug from the vein into surrounding skin and tissue (extravasation). It is also used for other conditions