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Last reviewed 2026-09-01 · statute and FDA text read 2026-09-01
503A vs 503B: who made your compounded drug, and who inspects them
A 503A pharmacy compounds for one named patient on one prescription and answers to its state board of pharmacy. A 503B outsourcing facility registers with the FDA, is inspected by the FDA, and is held to current good manufacturing practice. The label on a compounded prescription names one or the other; that name decides who inspected it and where its record lives.
What the statute says
Both categories live in the Federal Food, Drug, and Cosmetic Act. Section 503A describes compounding by a licensed pharmacist or physician for an identified patient:
Sections 351(a)(2)(B), 352(f)(1), and 355 of this title shall not apply to a drug product if the drug product is compounded for an identified individual patient based on the receipt of a valid prescription order or a notation, approved by the prescribing practitioner, on the prescription order that a compounded product is necessary for the identified patient, if the drug product meets the requirements of this section, and if the compounding- (1) is by- (A) a licensed pharmacist in a State licensed pharmacy or a Federal facility, or (B) a licensed physician, on the prescription order for such individual patient made by a licensed physician or other licensed practitioner authorized by State law to prescribe drugs …
Section 503B, added by the Drug Quality and Security Act of 2013, defines the second category:
(4)(A) The term “outsourcing facility” means a facility at one geographic location or address that- (i) is engaged in the compounding of sterile drugs; (ii) has elected to register as an outsourcing facility; and (iii) complies with all of the requirements of this section. (B) An outsourcing facility is not required to be a licensed pharmacy. (C) An outsourcing facility may or may not obtain prescriptions for identified individual patients.
The three sections that 503A exempts are the ones that make a drug a manufactured product: current good manufacturing practice (351(a)(2)(B)), adequate directions for use (352(f)(1)) and premarket approval (355). Section 503B exempts a facility from the second and third but not the first. That is the whole difference in one sentence, and the FDA puts it plainly:
Quality standards for compounded drugs differ depending on the setting where compounding occurs. Drugs compounded in outsourcing facilities are subject to current good manufacturing practice (CGMP) requirements. By contrast, drugs compounded by a licensed pharmacist in a state-licensed pharmacy or federal facility, or by a physician, in accordance with the conditions of section 503A of the FD&C Act, are not.
Who inspects whom
Generally, state boards of pharmacy have primary responsibility for the day-to-day oversight of state-licensed pharmacies that are not registered with FDA as outsourcing facilities. FDA does conduct surveillance and for-cause inspections of state-licensed pharmacies that are not registered as outsourcing facilities.
Facilities that register with FDA as outsourcing facilities under section 503B are primarily overseen by FDA and inspected by FDA according to a risk-based schedule.
Registration is annual. Section 503B(b)(1)(A) requires an outsourcing facility to register with the FDA “during the period beginning on October 1 and ending on December 31 of each year” and to say whether it intends to compound a drug on the shortage list. The FDA publishes the resulting list, with the date of each facility's last inspection and what followed; that list is what this site republishes, currently as of 2026-09-02.
Side by side
| 503A pharmacy | 503B outsourcing facility | |
|---|---|---|
| Compounds for | An identified individual patient on a valid prescription (503A(a)) | An outsourcing facility “may or may not obtain prescriptions for identified individual patients” (503B(d)(4)(C)) |
| Primary oversight | State board of pharmacy (FDA Q&A) | FDA (FDA Q&A) |
| Inspection | State board; FDA surveillance and for-cause inspections (FDA Q&A) | FDA, “according to a risk-based schedule” (FDA Q&A) |
| Manufacturing standard | Exempt from CGMP under 503A(a) | Subject to CGMP (FDA Q&A; 503B(a) carries no CGMP exemption) |
| Must be a licensed pharmacy? | Yes: “a licensed pharmacist in a State licensed pharmacy” (503A(a)(1)(A)) | “Not required to be a licensed pharmacy” (503B(d)(4)(B)) |
| Registration with FDA | None required under 503A | Annual, October 1 to December 31 (503B(b)(1)(A)) |
| Where the public record lives | Its state board of pharmacy | The FDA's register, republished on this site |
Parenthetical references are to the statute subsections and FDA page quoted above; nothing in the table is our characterisation.
What it means for the label you are holding
A compounded prescription is labelled with the pharmacy or facility that made it, which is often not the telehealth brand that sold it. That name is the only thing you need.
- Type the name into the lookup. If it matches, the maker is an FDA-registered 503B facility, and its FDA record (last inspection, Form 483, recall, action taken) is on this site with the FDA's date.
- No match means 503A, almost always. Most compounding pharmacies never register with the FDA. Their license and any disciplinary history are held by the state board for the state on the label; the National Association of Boards of Pharmacy keeps the directory of every board.
- Neither result is a verdict. Registration is not endorsement, and a state license is not a warning. What each gives you is a public record with a regulator's name on it, and the FDA's own framing for when a compounded drug belongs in the picture at all:
Compounded drugs should only be used in patients whose medical needs cannot be met by an FDA-approved drug.
Common questions
Is a 503B outsourcing facility a pharmacy?
Not necessarily. Section 503B says an outsourcing facility "is not required to be a licensed pharmacy" and "may or may not obtain prescriptions for identified individual patients." It is a facility that has elected to register with the FDA and is inspected by the FDA. Many are also licensed by their state; that license is a separate record held by the state board.
Can a 503A pharmacy ship compounded drugs to other states?
The statute ties this to a memorandum of understanding between the state and the FDA. Where the state has not signed one, section 503A limits out-of-state distribution to 5 percent of the pharmacy's total prescription orders. Whether a particular pharmacy is within that limit is not something any public register shows; the state board is the place to ask.
Is a 503B facility safer than a 503A pharmacy?
This site does not say, and neither does the statute. The two sections describe different oversight: state boards for 503A pharmacies, FDA inspection and manufacturing-practice requirements for 503B facilities. What you can read is the record: for a 503B facility, the FDA's inspection columns on this site; for a 503A pharmacy, the license and any disciplinary history at its state board.
Which kind filled my telehealth prescription?
The label on the compounded drug names the pharmacy or facility that made it. Type that name into the lookup on this site. If it appears, it is an FDA-registered 503B facility and its FDA record is here. If it does not, it is most likely a state-licensed 503A pharmacy, and its state board of pharmacy holds its record.
Why is my pharmacy not on the FDA list at all?
Because most compounding pharmacies are 503A pharmacies, and the FDA's list covers only facilities that registered under section 503B. Absence from the FDA list is not evidence of anything except that the pharmacy did not register as an outsourcing facility.
Sources: 21 U.S.C. 353a and 21 U.S.C. 353b (U.S. Code, Office of the Law Revision Counsel); FDA, Compounding and the FDA: Questions and Answers; all read 2026-09-01. Statute text is quoted with subsection numbering preserved and omissions marked. See methodology.