What compounding actually is
Pharmaceutical compounding is the preparation of a custom medication for an individual patient — typically because a commercial product doesn't exist at the needed dose, form, or combination. Compounding pharmacies have been part of US healthcare for over a century.
503A vs 503B
A 503A pharmacy compounds medications for individual patients under a prescription. A 503B "outsourcing facility" registers with the FDA, follows current Good Manufacturing Practices (cGMP), and can produce batches for healthcare providers. Both are regulated; 503B operates under stricter manufacturing standards.
Compounded ≠ generic
Generics are FDA-approved as finished products and must meet applicable approval requirements. Compounded drugs are not FDA-approved or generic, and equivalence to a brand product must not be assumed. The exact ingredient form, concentration, route, excipients, and source require independent review.
How to evaluate quality
- State licensure and Board of Pharmacy standing of the compounding pharmacy
- PCAB or USP <797>/<795> compliance documentation
- Public adverse-event history (FDA recall lookups)
- Beyond-use date and storage conditions on your label
- Clear sourcing documentation for the active ingredient