Category 1, Category 2 and the 503A bulks list in 2026

Twelve peptides left FDA's Category 2 in April, GHK-Cu went back into Category 1 in May, and an advisory committee voted in July. None of it put a peptide on the 503A bulks list. A dated tracker.

By Touchstone PeptidesSeptember 22, 202610 minute read

FDA's compounding framework moved three times on research peptides in 2026, and most coverage folds the three into one headline. On April 22 FDA's Category 2 page moved twelve peptides, BPC-157 among them, into a section headed "nominated but withdrawn"; in May, GHK-Cu for non-parenteral routes went back into Category 1 after a nominator clarified what it had withdrawn; on July 23 and 24 the Pharmacy Compounding Advisory Committee voted on seven of the withdrawn peptides. None of those events placed a peptide on the 503A bulks list, and none changed what a research-use-only supplier may or may not do.

What is the 503A bulks list?

Section 503A of the Federal Food, Drug, and Cosmetic Act lets a licensed pharmacist in a state-licensed pharmacy, or a physician, compound a drug for an individual prescription without that drug going through FDA approval. The exemption comes with conditions, and one of them is about the raw material. A bulk drug substance may be used under 503A only if it meets one of three tests, which FDA's own page states as: it complies with a USP or NF monograph, or, where no monograph exists, it is a component of an FDA-approved drug, or it appears on "FDA's list of bulk drug substances that can be used in compounding."

That third list is the 503A bulks list. It is created by rulemaking, not by a web page. The criteria FDA uses to add or exclude a substance were set in a final rule published February 19, 2019 (84 FR 4696), and the list itself is codified at 21 CFR 216.23. In the 2024 edition of the Code of Federal Regulations, paragraph (a) of that section holds six substances, five of them for topical use only, and paragraph (b) names four substances FDA evaluated and decided to exclude. No peptide is in either paragraph.

What do Category 1, Category 2 and Category 3 mean?

Because the list is short and rulemaking is slow, FDA has run an "Interim Policy on Compounding Using Bulk Drug Substances Under Section 503A" since the nominations process began. Every nominated substance is sorted into one of three categories, defined on FDA's 503A page:

Category	FDA's definition	What follows
Category 1	Substances "nominated with sufficient supporting information for FDA to evaluate them, and do not appear on any other list"	"FDA does not intend to take action against a compounder for compounding drugs using bulk drug substances listed in category 1, provided that the conditions described in the guidance document are met."
Category 2	Substances with sufficient information but where "FDA has identified significant safety risks"; FDA "does not intend to adopt the policy described for the substances in category 1"	No enforcement discretion
Category 3	Substances "nominated with insufficient supporting information for FDA to evaluate them"	"not eligible for the policy that applies to substances in category 1"

Two features of this table explain most of the confusion in 2026. Category 1 is not approval and not the bulks list; it is a statement that FDA does not intend to act while it evaluates. And a substance can leave a category without entering another one: if the nomination is withdrawn, there is nothing left to categorise.

Event one: April 22, 2026, twelve peptides leave Category 2

On September 29, 2023 FDA added a batch of eighteen entries to Category 2. Fourteen were under 503A (thirteen peptides plus ibutamoren mesylate) and four under 503B (GHRP-2, GHRP-6, ipamorelin acetate and tranilast). The archived version of FDA's Category 2 page that was live on April 21, 2026 still listed the 503A peptides with that date.

On the version dated April 22, 2026, twelve of them sit under a new heading, "Bulk drug substances nominated but withdrawn," with one explanatory sentence: "This list of bulk drug substances previously in category 2 of the interim policies were withdrawn by the nominators." The twelve are BPC-157, cathelicidin LL-37, dihexa acetate, emideltide (DSIP), epitalon, GHK-Cu for parenteral routes, KPV, Melanotan II, PEG-MGF, MOTS-c, Semax and the thymosin beta-4 fragment sold as TB-500. Four other peptides in the same section, AOD-9604, CJC-1295, Selank acetate and thymosin alpha-1, had already left Category 2 by September 27, 2024, when FDA's page listed them separately under "Other bulk drug substances that may present significant safety risks," so they are not part of the 2026 event at all.

FDA did not re-evaluate these substances. The nominators, identified in FDA's July briefing document as Wells Pharmacy Network and LDT Health Solutions on behalf of the International Peptide Society, withdrew their nominations. The safety text FDA wrote for each substance in 2023 is still on the page. For BPC-157 it reads:

Compounded drugs containing BPC-157 may pose risk for immunogenicity for certain routes of administration and may have complexities with regard to peptide-related impurities and active pharmaceutical ingredient (API) characterization. FDA has identified no, or only limited, safety-related information for the proposed routes of administration.FDA, Category 2 page, content current as of April 22, 2026

So after April 22 the twelve are in no category, are not on the bulks list, and are not covered by the Category 1 enforcement discretion. Counts of "fourteen" or "nineteen" peptides, and dates of April 15 or April 23, appear in secondary coverage and not in any FDA document.

Event two: May 2026, GHK-Cu goes back into Category 1

GHK-Cu is the one peptide with a different story, and FDA's May 14, 2026 Category 1 document tells it verbatim:

GHK-Cu (except for injectable routes of administration) was removed from category 1 on April 22, 2026, because the nominations for GHK-Cu were withdrawn by the nominators. On May 5, 2026, one of those nominators clarified that it intended to withdraw only its nomination of the injectable route of administration with respect to GHK-Cu and would like to retain its nomination for GHK-Cu for non-injectable routes of administration. GHK-Cu (except for injectable routes of administration) will be added back to category 1.FDA, Bulk Drug Substances Nominated for Use in Compounding Under Section 503A, updated May 14, 2026

The same document says FDA "intends to consult the Pharmacy Compounding Advisory Committee (PCAC) before the end of February 2027 regarding the potential inclusion of GHK-Cu on the 503A bulks list." As of September 21, 2026, GHK-Cu for non-parenteral routes and vasoactive intestinal peptide are the only 503A Category 1 entries among the research peptides discussed here (glutathione, a tripeptide, is also listed). A research vial of GHK-Cu, the copper complex of the tripeptide Gly-His-Lys, is a different article from a compounded topical.

Event three: July 23 and 24, 2026, the PCAC votes

FDA announced the meeting in the Federal Register on April 16, 2026 (91 FR 20465, docket FDA-2025-N-6895); the notice says nothing about Category 2 or withdrawals. The committee met virtually on July 23 and 24 and took fourteen votes, one for the free base and one for the acetate salt of each of seven peptides: BPC-157, KPV, TB-500 and MOTS-c on the first day, emideltide (DSIP), Semax and epitalon on the second. FDA's briefing document notes for each substance that the nomination "was withdrawn by the nominator" but that "FDA is electing to proceed" with the presentation anyway.

FDA's staff position was the same for all fourteen: "FDA is proposing that BPC-157 (free base) NOT be included on the 503A Bulks List," and likewise for each of the others. The voting question put to the committee was equally plain: "VOTE: Should BPC-157 (free base) be placed on the list?"

What the votes were is a press fact rather than an FDA fact. The meeting page, last updated August 6, 2026, lists only pre-meeting materials; FDA has posted no minutes and no vote record. TIME and OpenLoop Health reported BPC-157 at 8 yes, 6 no, 1 abstention, majorities in favor for six of the seven peptides, and emideltide voted down 6 to 7. The archived webcast is the only primary record. Two sentences from FDA's own documents frame what any tally means:

The FDA does not intend to issue a final determination on the issues at hand until input from the advisory committee process has been considered and all reviews have been finalized.FDA, PCAC Briefing Document, July 23-24, 2026

Advisory committees make non-binding recommendations to the FDA, which generally follows the recommendations but is not legally bound to do so.FDA, PCAC meeting page, content current as of August 6, 2026

Adding a substance to the bulks list requires rulemaking under section 503A(c). As of September 21, 2026 no proposed rule, Federal Register notice or press release on any of the seven peptides has appeared on fda.gov or federalregister.gov. The BPC-157 thread continues in BPC-157 in 2026: not banned, not approved, not compoundable.

Tracker: where each peptide stands as of September 21, 2026

Substance	September 29, 2023	April 22, 2026	July 2026 PCAC (FDA proposed not to list; tally per press)	503A Category 1?	On 503A bulks list?
BPC-157	503A Category 2	Withdrawn	8-6-1	No	No
TB-500 (thymosin beta-4 fragment)	503A Category 2	Withdrawn	8-6-1	No	No
KPV	503A Category 2	Withdrawn	8-6-1	No	No
MOTS-c	503A Category 2	Withdrawn	7-5-2	No	No
Semax	503A Category 2	Withdrawn	8-5-0	No	No
Epitalon	503A Category 2	Withdrawn	7-4-0	No	No
Emideltide (DSIP)	503A Category 2	Withdrawn	6-7-0	No	No
Melanotan II, LL-37, dihexa, PEG-MGF	503A Category 2	Withdrawn	Not on the agenda	No	No
GHK-Cu (non-parenteral)	503A Category 1	Withdrawn, then clarified May 5	Consultation promised before end of February 2027	Yes	No
AOD-9604, CJC-1295, Selank, thymosin alpha-1	No dated entry on FDA's page	Outside Category 2 by September 27, 2024; listed as withdrawn on the April 22, 2026 page	Not on the agenda	No	No
Kisspeptin-10	503A Category 2	Still 503A Category 2	Not on the agenda	No	No
GHRP-2, GHRP-6, ipamorelin acetate	503B Category 2	Still 503B Category 2	Not on the agenda	No	No

Rows are read from FDA's Category 2 page, the May 14, 2026 Category 1 document, the PCAC documents and the two press reports named above.

What changed for pharmacies, and what changed for research suppliers

For a 503A pharmacy the practical position is the same on September 21, 2026 as it was on April 21. A substance with no monograph, no approved-drug parent and no place on the bulks list cannot be used under 503A, and the Category 1 discretion does not cover a withdrawn nomination. GHK-Cu for non-parenteral routes is the exception, and it was in Category 1 before 2026 too. Category 2 status, while it lasted, was a public flag; withdrawal removed the flag, not the text behind it. For 503B outsourcing facilities the lists are different, and the peptides still in 503B Category 2 are GHRP-2, GHRP-6 and ipamorelin acetate.

For a research-use-only supplier none of this ever applied. The 503A framework governs what a pharmacy may compound for a prescription; it says nothing about the sale of a chemical for laboratory use. A research vial of BPC-157 was not compoundable on April 21, is not compoundable on September 21, and was never sold for that purpose; how this site sources it is on the provenance page. The three supply chains, 503A, 503B and research-use-only, are laid out in 503A, 503B and research-use-only: three supply chains that do not mix, and the per-molecule status lines are collected in Approved, investigational, or neither: a status table.

Sources

For laboratory research use only. Not a drug, not a supplement, and nothing here is a claim about what any of this material does in a person or an animal.

Two things before you come in.