Educational only. Not medical or legal advice. This site summarizes public U.S. government statements as of October 22, 2026. It does not sell, recommend or endorse any product, and it does not give dosing information. Talk to a licensed clinician about any medicine, and check the linked FDA pages for the latest version.
| 503A | 503B | |
|---|---|---|
| Who | State-licensed pharmacists and physicians [FDA] | Facilities registered with FDA as outsourcing facilities [FDA] |
| Bulk substances | Must meet a USP/NF monograph, be a component of an FDA-approved drug, or be on FDA's 503A bulks list [FDA] | Separate 503B bulks list; copies of approved drugs restricted unless on the shortage list [FDA] |
| Manufacturing standard | State pharmacy rules (see your state board) | Not exempt from current good manufacturing practice (CGMP) requirements [FDA] |
| FDA registration | No FDA outsourcing registration | Must register and re-register every year, with an annual fee [FDA] |
| FDA inspection | Primarily state oversight | FDA inspects on a risk-based schedule [FDA] |
| "Copies" of approved drugs | Restricted if done regularly or in inordinate amounts [FDA] | Restricted unless the approved drug is on the shortage list [FDA] |
Key FDA factCompounded drugs are not FDA-approved, whether made under 503A or 503B. [FDA]
Rows marked "state board" or "primarily state oversight" are our plain-language summaries, not FDA quotes.