Medical director requirements are among the most misunderstood and unevenly enforced rules in aesthetic practice. Unlike FDA device clearance or manufacturer credentialing, which apply uniformly across the country, medical director supervision is governed by state medical boards, state nursing boards, and sometimes local health departments. The rules vary dramatically: some states require on-site presence for all injections; others permit remote supervision of nurse injectors; still others have no explicit statutory requirement at all. For a practice owner, this variation creates real compliance risk and liability exposure. A medical director who is present but not actively supervising, or who supervises remotely without proper protocols, can expose the practice to regulatory action, malpractice liability, and loss of licensure. This page explains what medical director supervision actually entails, how liability attaches, and what the state-level landscape looks like—so you can build a compliant structure and understand your exposure.