California Code, Business and Professions Code - BPC § 17533.10

It shall be unlawful for any person, firm, corporation, or association, in any newspaper, magazine, circular, form letter, or open publication, published, distributed, or circulated in this state, including over the Internet, or on any billboard, card, label, or other advertising medium, or by means of any other advertising device, to advertise the sale of anabolic steroids, as defined in subdivision (f) of Section 11056 of the Health and Safety Code, unless there is conspicuously displayed or stated in connection with the name and description of any of those anabolic steroids, a direct and unequivocal statement that will clearly indicate that the possession by, or sale to, an ultimate consumer of anabolic steroids is a crime punishable by a substantial fine and imprisonment, unless upon the prescription of a physician, dentist, podiatrist, or veterinarian, licensed to practice in this state, pursuant to Sections 11377, 11378, and 11379 of the Health and Safety Code.