PCAC, the 503A bulks list, and the Category 1 and 2 status of peptides people ask about

Section 503A lets a pharmacy compound from a bulk substance only if the substance has a USP or NF monograph, is a component of an FDA-approved drug, or appears on a list FDA develops by regulation, the 503A bulks list. Most of the peptides sold as "research" products have no monograph and are in no approved drug. So their status comes down to the list, the interim categories FDA used while building it, and the advisory committee that recommends what goes on it.

How the list is built

1. Nomination. Anyone may nominate a substance, with information on its physical and chemical characterisation, safety, effectiveness and history of use in compounding.
2. FDA review and PCAC. FDA evaluates the nomination and takes it to the Pharmacy Compounding Advisory Committee, twelve voting members drawn from compounding, manufacturing, pharmacy and medicine. The committee votes on whether to recommend inclusion. FDA is not bound by the vote.
3. Rulemaking. FDA publishes a proposed rule, takes comments, and issues a final rule. The first final rule, in February 2019, placed six substances on the list and found four ineligible; a September 2019 proposed rule added five candidates and rejected 26.

Until a substance reaches step 3, it is not on the list.

The interim categories

Because rulemaking is slow and nominations numbered in the hundreds, FDA published an interim policy sorting nominated substances into three categories. FDA's definitions, from its 503A bulks page:

• Category 1. May be eligible for the list, nominated with sufficient supporting information, and not on any other list. FDA does not intend to take action against compounding with these while it evaluates them, provided the other 503A conditions are met.
• Category 2. Nominated with adequate information, but FDA has identified significant safety risks relating to their use in compounding pending further evaluation. FDA may take action.
• Category 3. Nominated with insufficient information to evaluate. Not covered by the interim policy; FDA may take action.

On January 7, 2025 FDA revised the policy: substances nominated on or after that date are not placed in any category. Substances already in Category 1 stay under the interim policy until FDA lists them or removes them for safety reasons.

Peptides and Category 2

On September 29, 2023 FDA placed a group of peptides in Category 2 of the 503A list, citing in each case a risk of immunogenicity and, for most, little or no human safety data. FDA's Category 2 page, content current as of April 22, 2026, now shows two groups.

Still listed in Category 2 on that page (with the section and date FDA gives):

Listed by FDA as nominated but withdrawn from Category 2 (FDA's safety concerns remain on the page): AOD-9604, BPC-157, cathelicidin LL-37, CJC-1295, dihexa, emideltide (DSIP), epitalon, GHK-Cu (injectable), KPV, PEG-MGF, melanotan II, MOTS-c, selank, semax, thymosin alpha-1, and thymosin beta-4 fragment (TB-500). Withdrawal from Category 2 does not place a substance in Category 1 or on the list; it means the nomination was withdrawn or FDA moved it into the committee process.

Substances people ask about that do not appear on the Category 2 page at all, as of that date: sermorelin, tesamorelin, NAD+, PT-141 (bremelanotide) and 5-amino-1MQ. Absence from the Category 2 page is not a status. Tesamorelin and bremelanotide are active ingredients of approved drugs (Egrifta, Vyleesi), which is a separate route to eligibility under 503A; the others would need to be checked against the Category 1 and 3 lists FDA publishes on the bulks page.

What PCAC did in 2024 and 2026

• October 29, 2024: the committee considered ipamorelin, ibutamoren, L-theanine and kisspeptin-10. FDA's briefing materials recommended against inclusion for each.
• December 2024: AOD-9604, CJC-1295 (several forms) and thymosin alpha-1 were considered.
• July 23 and 24, 2026: BPC-157, KPV, TB-500 and MOTS-c on the first day; emideltide, semax and epitalon on the second, each in free base and acetate forms, with proposed uses ranging from ulcerative colitis to insomnia. FDA's meeting page, content current as of August 6, 2026, carries the agenda and briefing documents. As of our check it did not carry vote tallies or minutes. Trade and legal press have reported that the committee recommended most of the day-one and day-two peptides by narrow margins and rejected emideltide; we have not been able to confirm the tallies on an FDA page and do not repeat them as fact.

A recommendation, if that is what happened, is step 2 of 3. Nothing is on the list until a final rule says so.

What this means when you are offered a peptide

Ask which route makes the substance eligible under 503A: a USP monograph, an approved drug that contains it, or a place on the 503A bulks list or in Category 1. If the answer is "it is legal because it is sold for research," the seller is telling you it is not a compounded drug at all; see salt forms and research use only. Our peptide reference site covers the human evidence for each of these substances separately, and the FormBlends state of peptides and GLP-1 regulation 2026 report puts the regulatory picture in one place.