503A Pharmacy

A 503A pharmacy is a traditional compounding pharmacy — one that prepares customised medications for individual patients on a prescription-by-prescription basis. Under Section 503A of the Federal Food, Drug, and Cosmetic Act (FD&C Act), these pharmacies can compound drugs using bulk active pharmaceutical ingredients (APIs) that are on the FDA's approved bulk substances list. The prescription must come from a licensed practitioner for a specific, identified patient. Batch production without individual prescriptions is not permitted under 503A. The PCAC (Pharmacy Compounding Advisory Committee) reviews which bulk substances can be used by 503A pharmacies — that's what the July 23–24 2026 meeting is about for peptides like BPC-157, MOTS-c, and KPV. The 503A track is distinct from 503B outsourcing facilities, which can produce larger batches without patient-specific prescriptions but are subject to more intensive FDA oversight. Most research peptides, when prescribed, flow through 503A pharmacies. One hard constraint: 503A pharmacies cannot compound drugs that are "essentially copies" of FDA-approved drugs with active NDAs. That's why tesamorelin (Egrifta) and bremelanotide (Vyleesi) cannot be compounded — they have approved equivalents.