Biological and Clinical Applications of Dimethyl Sulfoxide: Evidence and Safety Considerations

Dimethyl sulfoxide (DMSO) is a polar aprotic solvent used in biomedical research, pharmaceutical formulation, some clinical applications, and cryopreservation. Here we review molecular activity related to DMSO and selected clinical applications including interstitial cystitis/bladder pain syndrome (IC/BPS), musculoskeletal and traumatic injury, central nervous system (CNS) trauma, cardiovascular and ischemic injury, historical oncology research, local applications, cryopreservation and safety. Of the applications discussed, intravesical DMSO has the clearest contemporary clinical support in selected patients with IC/BPS, particularly those with Hunner-type disease, although its role in non-Hunner disease remains uncertain. This concentration may partly reflect DMSO's limited regulatory approval for therapeutic use, rather than comparative evaluation across indications. Mixed findings have been reported for other applications: modest pain relief has been observed in knee osteoarthritis, whereas no benefit has been found in systemic sclerosis ulcers, where substantial skin intolerance has also been reported. Small uncontrolled clinical series reported reductions in intracranial pressure following intravenous DMSO administration. Walker's monograph separately described neurological recovery after CNS trauma, but concurrent treatment and incomplete documentation limit causal attribution. Reduced intracranial pressure alone does not establish long-term neurological benefit. Historical oncology reports described DMSO-containing hematoxylin preparations, including "haematoxylon", but evidence of antitumor efficacy remains insufficient. Historical ocular and otic applications involved diverse formulations but limited controlled clinical assessment. Cardiovascular protection remains supported mainly by preclinical research. DMSO is an effective cryoprotectant but residual exposure may cause infusion reactions and removal after thaw adds to the processing burden and potential cell loss. Biological activity and risk vary with concentration, route, duration, formulation, material quality, and biological setting. Historical narratives identify questions for further study but do not establish clinical efficacy. This review summarizes reported DMSO effects and risks, examines study limitations, and identifies unresolved research questions.