Cal. Health & Saf. Code § 109505
DMSO sold in California other than by prescription shall be labeled by the manufacturer, distributor, or seller to contain a description of all of the contents in the solution, statement of purity, the percent of DMSO in the solution, and the manufacturer's name and address.
The label shall contain (a) the name and address of the distributor of the DMSO, if any, (b) the name and address of the manufacturer of the finished DMSO, and (c) the manufacturer's lot or control number. Finished DMSO means DMSO that requires no further manufacture prior to retail sale other than packaging or labeling. Whenever DMSO is sold or otherwise supplied, other than by prescription, the seller or supplier shall give additional printed material to the person receiving the DMSO that provides adequate warning against use that may be dangerous to the health of the user, and information that prescriptive DMSO is available from a physician.
The label of DMSO sold pursuant to this section shall contain the following statement: "It is unlawful to represent in any way that this product is useful or safe to use for medicinal purposes." The label shall include appropriate precautionary measures for proper handling and first aid treatment and a warning statement to keep the product out of reach of children.
Ca. Health and Saf. Code § 109505