What does Mississippi prohibit in med spa advertising?

Short answer
Any truthful, non-misleading claim — a physician may advertise in any medium — but not "flamboyant claims" about professional excellence, and every ad must name a responsible physician identified as M.D., D.O., or D.P.M.

The advertising provisions that reach a Mississippi medical practice in the sections cited here are the medical board’s advertising rule and the health care practitioner advertising act. The medical practice act makes flamboyant claims of professional excellence unprofessional conduct. The Board’s rule lets a physician advertise provided the communication is not misleading by omission, contains no false or misleading statement, and does not otherwise deceive; every advertisement must name at least one responsible physician, identified as M.D., D.O., or D.P.M. rather than only “Doctor.” The advertising act requires any advertisement naming a practitioner to identify the type of license held and to be free of deceptive or misleading information, defines deceptive to include misstating the practitioner’s profession, skills, training, expertise, education, board certification, or licensure, requires the license type to be posted in the office, and makes a violation unprofessional conduct subject to discipline by the practitioner’s own board. None of these provisions mentions before-and-after photographs, testimonials, or discounts.