An overview of the regulatory framework for pharmacy compounding under Sections 503A and 503B of the FD&C Act, including implications for peptide products.
Filed under regulation, written for clinician, pharmacist-compounder, regulator-compliance, founder-operator, evidence level regulatory-update.
Not medically reviewed. Last updated 2026-05-05. Nothing here is medical advice.
Pharmacy compounding is regulated under two sections of the Federal Food, Drug, and Cosmetic Act: Section 503A (traditional compounding pharmacies) and Section 503B (outsourcing facilities).
Under 503A, licensed pharmacies may compound drugs for individual patients based on valid prescriptions. Key requirements include:
503B facilities voluntarily register with the FDA and are subject to more rigorous oversight:
Several peptides have been nominated for inclusion on the 503A bulks list. The FDA's Pharmacy Compounding Advisory Committee reviews these nominations and makes recommendations. Some peptide substances have been placed in Category 2, meaning the FDA has identified significant safety risks.
Compounded drugs are not FDA-approved. The FDA does not verify their safety, effectiveness, or quality before they are marketed. Patients using compounded peptide products should understand this distinction.
This article provides regulatory education only and does not recommend specific compounding pharmacies or products.
More guides: All guides, Safety centre, Peptide library.