Review (3/5): 0.1% Unknown solvent
There are no ingredients listed, only "99.9% pure dmso", but given DMSO's ability to cross the skin barrier, it's vitally important to either publish a MSDS, or at the very least print an ingredients list on the side for edification of what else might come along with the DMSO (into the body).
Used extremely sparingly, and it worked as expected - although didn't get a blood panel after, so can't tell if it caused any secondary effects.