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← Back to Blog Published on July 15, 2026

503A vs. 503B: two compounding lists, two different fights

The peptide review and the compounded-Ozempic crackdown are both about "compounding", but they run on two separate legal tracks. Here's how to tell them apart.

When people hear that the FDA is "deciding whether pharmacies can make peptides," they often blend it with the parallel story about compounded versions of Ozempic-style weight-loss drugs. The two stories are related, but legally distinct, and the difference comes down to two sections of federal law, 503A and 503B, each with its own separate list of bulk ingredients that a pharmacy is allowed to use.

503A covers traditional compounding pharmacies filling a prescription for an individual, identified patient. A raw active ingredient, a "bulk drug substance" that has no U.S. Pharmacopeia monograph and isn't a component of an FDA-approved drug, can only be compounded under 503A if the FDA has placed it on the 503A Bulk Drug Substances List. That list is exactly what the Pharmacy Compounding Advisory Committee will weigh for seven peptides, BPC-157, KPV, TB-500, MOTS-c, emideltide (DSIP), semax and epitalon, when it meets July 23-24. [1]

503B covers "outsourcing facilities", larger operations that make batches under stricter manufacturing rules without a patient-specific prescription, typically for clinics and hospitals. They draw from a separate 503B bulks list. That is the track in the GLP-1 story: the FDA has proposed formally excluding semaglutide, tirzepatide and liraglutide from the 503B bulks list, which would bar outsourcing facilities from mass-compounding those drugs from bulk regardless of future shortages. [2]

So: different lists, different questions, different stakes. One asks whether a pharmacist can compound a peptide one prescription at a time; the other asks whether a facility can batch-produce a proven, patented drug that's no longer in shortage. On the science of the peptides themselves we take no position, none of the seven has been evaluated by the FDA for the compounded uses at issue, and the agency's own reviewers flagged limited human data ahead of the meeting. We make no claim about whether any of them works. [3]

Where we do have a stated view is on policy, and we disclose it plainly: Peppies is an independent, for-profit venture that would benefit only from a future legal, tested market, not from today's status quo. Our position is that a regulated pathway, whether licensed 503A compounding under proper controls or an approved drug, is safer for people than the unregulated grey market, where products sold "for research only" arrive with no dosing, no purity guarantee and no oversight. We respect legitimate licensed compounding and legitimate pharmaceutical patents alike; our argument is with the grey market, not with either. Which substances land on which list is, more than any online seller, what actually decides safe access. [4]

Sources

  1. FDA, July 23-24, 2026 PCAC meeting notice (503A peptide review)
  2. Pharmacy Times, FDA moves to exclude GLP-1s from the 503B bulks list
  3. Endpoints News, FDA reviewers oppose allowing seven peptides for compounding
  4. Regulations.gov, docket FDA-2025-N-6895

The moment that counts comes later. When the FDA opens the public comment window that carries legal weight, we'll tell you. Get notified →

Related Questions

Frequently Asked Questions

Who's behind Peppies, and how do you make money?

Peppies was founded by an entrepreneur with a track record of turning confusing consumer problems into organized public action. We don't sell peptides, and we're transparent about the incentive: we'd benefit only from a legal, regulated market - the same outcome that makes people safer - not from today's grey market. Full disclosure is here.

If the committee votes "yes," can I buy them right away?

No. The vote is only a recommendation. Real access would change only if the FDA later opens a formal rulemaking - which is also the stage with a public comment window where an ordinary person's input carries legal weight. How the process works →

What's the difference between a compounding pharmacy and an online seller?

A licensed compounding pharmacy is inspected, dispenses against a prescription, and must meet identity, potency and sterility standards. An anonymous online seller does none of that. Telling them apart - and reporting the illegal ones - is covered step by step in Safety & the Grey Market.

Will my peptide be "banned"?

Not exactly. The review is about whether pharmacies may legally compound these substances - building a legal, regulated pathway, not adding a new prohibition. Today most already have no cleared legal channel. Follow the status on the tracker.