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What is a 503A pharmacy, and what may it make?

Peptide Chooser editorial team. Checked 2 Nov 2026.

Short answer

A 503A pharmacy is an ordinary state-licensed pharmacy that makes medicines for one patient at a time, on a prescription.1 It may use a raw ingredient only if the law allows it, for example from the FDA's 503A bulks list; while the FDA reviews nominated ingredients, it sorts them into three categories, and only category 1 may be used, under conditions.1 A compounded medicine is never FDA approved.2

What is a 503A pharmacy?

Section 503A of the federal drug law covers state-licensed pharmacies and doctors who compound: they mix a medicine for a patient who has a prescription.1 Outsourcing facilities work under a different section, 503B, with their own list.5

A compounded medicine is not FDA approved. The FDA does not check its safety, effectiveness or quality before it is sold.2

What may a 503A pharmacy compound?

It may make a medicine from a raw ingredient (a bulk drug substance) only if that ingredient meets one of the law's conditions, for example by being on the FDA's 503A bulks list.1

Many ingredients have been nominated for that list. While the FDA reviews them, it sorts them into three categories:1

  • Category 1: nominated with enough information for the FDA to review it. The FDA does not intend to act against a pharmacy that uses it, if the conditions in its guidance are met.
  • Category 2: nominated with enough information, but the FDA found significant safety risks. The category 1 policy does not apply, and the FDA may act against pharmacies that use it.
  • Category 3: nominated without enough information to review it. It can be nominated again with more.

Where do the peptides we track sit?

From our database, which reads the FDA's lists:

A substance can sit in two lists when the FDA treats its routes of use apart. GHK-Cu is the example: GHK-Cu "except for injectable routes of administration" is in category 1,3 and GHK-Cu "for injectable routes of administration" is among the substances whose nomination was withdrawn.4 So the category 1 policy covers GHK-Cu that is not injected; for shots, the nomination was withdrawn and the policy does not apply.

Each peptide's page on our site shows the status that applies and the FDA page behind it.

What do "category 1" and "nomination withdrawn" mean for a buyer?

Category 1 means a pharmacy may make a medicine with the ingredient for a patient with a prescription, under the FDA's conditions, while the review goes on.1 It does not mean the FDA approved it or found that it works.2

Nomination withdrawn means the request to add the substance to the list was withdrawn, so it is not in any of the three categories on that request. The FDA's page on risky substances names several peptides in that group, such as BPC-157 and TB-500, with the safety concerns it found.4 A pharmacy cannot rely on the category 1 policy for them.

Neither status says anything about research-use vials: those are not compounded medicines and are not approved for use in people.6

What are the rules for GLP-1 copies now?

While semaglutide and tirzepatide were in short supply, pharmacies could make copies of them. Both are now off the FDA's drug shortage list.5

For state-licensed 503A pharmacies, the time the FDA allowed for copies of semaglutide ended on 22 April 2025.5 The FDA has also warned that salt forms of semaglutide are a different ingredient from the one in the approved drugs.7 Our guide on compounded vs brand GLP-1 has more.

How can you tell which kind of pharmacy made a medicine?

Ask the clinic which pharmacy fills the prescription, and whether it is a 503A pharmacy or a 503B outsourcing facility. A brand medicine comes from its maker; a compounded one comes from the pharmacy that made it. The label on a compounded medicine names the pharmacy, so you can look up its state license.

None of this is legal or medical advice.

What to do next

See every peptide's statusAre peptides legal? guide

Sources

  1. FDA, Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act, current as of 14 May 2026: https://www.fda.gov/drugs/human-drug-compounding/bulk-drug-substances-used-compounding-under-section-503a-fdc-act
  2. FDA, Compounding and the FDA: Questions and Answers: https://www.fda.gov/drugs/human-drug-compounding/compounding-and-fda-questions-and-answers
  3. FDA, 503A Categories Update for Interim Policy on Compounding Using Bulk Drug Substances (the category lists): https://www.fda.gov/media/94155/download
  4. FDA, Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, current as of 22 Apr 2026: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
  5. FDA, FDA clarifies policies for compounders as national GLP-1 supply begins to stabilize: https://www.fda.gov/drugs/drug-alerts-and-statements/fda-clarifies-policies-compounders-national-glp-1-supply-begins-stabilize
  6. Drugs@FDA, searched through openFDA for BPC-157, GHK-Cu (also as copper tripeptide and prezatide) and TB-500 (also as thymosin beta-4): no approved product, 2 Nov 2026: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm
  7. FDA, FDA's Concerns with Unapproved GLP-1 Drugs Used for Weight Loss, current as of 1 Oct 2026: https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss