The vast majority of compounding pharmacies in the US are state licensed facilities classified under section 503A of the Federal Food, Drug, and Cosmetic Act (FD&C Act). A 503a pharmacy is allowed to compound drugs which are not FDA-approved, are not subject to the requirement that labeling bear adequate directions for use, and are not subject to CGMP requirements, and are provided to a patient only based on individual patient need (a valid prescription). These pharmacies are primarily under...