Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula (CH3)2SO. It can uniquely provide solubility to certain very polar small molecules, such as simple biomolecules with multiple protic functional groups.

DMSO's powerful ability to dissolve and carry anything with which it is mixed into the muscles, ligaments and blood can be an advantage when one wants to carry drugs or herbal extracts into the body through the skin.