Section 503A of the federal Food, Drug, and Cosmetic Act allows a state-licensed pharmacy or physician to compound a drug for a specific patient based on an individual prescription. These preparations are exempt from the FDA approval process, so they are not reviewed for safety and effectiveness or inspected batch by batch the way manufactured, FDA-approved drugs are.
Because oversight is lighter and quality depends heavily on the individual pharmacy, the strength, purity, and sterility of a 503A product can vary. This is a common route for compounded GLP-1 medications, and it is worth discussing the source and its risks with a prescriber before use.