Peptide Compounding: Which Substances Are on FDA's Category 2 List

FDA's interim bulk drug substance policy sorts every nominated compounding substance into three tiers, and Category 2 is the tier that tells a 503A pharmacist FDA has already identified a specific safety risk it is prepared to enforce against. Five peptides carry that flag on FDA's current list: GHRP-2, GHRP-6, Ibutamoren mesylate, Ipamorelin acetate, and Kisspeptin-10. A different set of peptides, BPC-157, KPV, TB-500, MOTS-c, Epitalon, and Semax, sits elsewhere, as withdrawn nominations FDA's Pharmacy Compounding Advisory Committee took up again in July 2026 for possible inclusion on the 503A Bulks List. Confusing the two groups, or assuming either is cleared for compounding, is where a pharmacy's exposure starts.

The Three Categories FDA Uses

Section 503A of the Federal Food, Drug, and Cosmetic Act lets a pharmacy compound with a bulk substance that has an applicable USP or NF monograph, is a component of an FDA-approved drug, or appears on FDA's 503A Bulks List. Substances nominated for that list but not yet added are sorted into three interim categories. Category 1 is the only tier that functions as a safe harbor: FDA will not pursue enforcement against a compounder using one, under specified conditions. Category 2 covers substances where FDA's review found a significant safety risk and reserves enforcement against a pharmacy that compounds one. Category 3 covers substances nominated with insufficient data. Since January 7, 2025, FDA has stopped sorting new nominations into any of the three categories. More on the distinction: 503A vs 503B: Which Framework Governs Your Compounding.

The Five Peptides Carrying the Flag Today

FDA's current Category 2 list names five peptides. GHRP-2 and GHRP-6, both flagged under 503B policy, carry immunogenicity concerns FDA ties to reported adverse events, including disrupted cortisol and insulin sensitivity from GHRP-6. Ipamorelin acetate, also flagged under 503B policy, carries the same immunogenicity concern, and FDA cites serious adverse events, including death, among the nominations it reviewed. Ibutamoren mesylate is flagged under both 503A and 503B policy for a documented risk of congestive heart failure. Kisspeptin-10 is flagged under 503A policy for insufficient safety data supporting its proposed routes of administration. FDA last updated this list on April 22, 2026.

A Different List: Nominations FDA's Committee Just Revisited

BPC-157, KPV, TB-500, MOTS-c, Epitalon, and Semax are not on Category 2 today. All six were nominated for the 503A Bulks List years ago and withdrawn by their nominators, until FDA's Pharmacy Compounding Advisory Committee took them up again at its meeting on July 23 and 24, 2026, alongside a seventh peptide, Emideltide. FDA's own briefing documents for that meeting proposed that none of the seven, including Emideltide, be placed on the 503A Bulks List, and the Committee's questions called for a vote on each one. A committee vote is advisory only. HHS Secretary approval and formal rulemaking still stand between any committee vote and an actual listing, and FDA has scheduled a second committee meeting before the end of February 2027 to review more peptides.

What a 503A Pharmacy Actually Has Today

Neither list gives a 503A pharmacy anything to compound against. The five Category 2 peptides sit outside the approved bulks list, with FDA's stated safety concerns on top of that. The six peptides the Committee discussed in July remain withdrawn nominations until FDA completes rulemaking. Compounding any of these eleven peptides does not meet section 503A's conditions, so the Act's cGMP requirement is not exempted, and the beyond-use date and USP 797/800 standards for sterile and non-sterile compounding apply, regardless of which tier the substance sits in.

A 503B outsourcing facility compounding the same peptides also carries its own mandatory adverse event reporting obligations for compounded preparations and its own 503B reporting obligations after registration, and neither duty pauses while a nomination's status is unsettled.

A Pharmacy Compounding Advisory Committee recommendation is not an FDA listing decision, and a withdrawn nomination is not a Category 1 safe harbor.

Why Early Legal Counsel Is Critical

It is critical that compounding pharmacies and prescribers promptly retain experienced healthcare defense counsel before continuing to compound, dispense, or prescribe a peptide carrying a Category 2 flag or an unresolved nomination, or in response to any FDA or state board inquiry about one. Early legal intervention can protect the provider's rights, ensure an accurate reading of where a substance actually sits across FDA's bulks-list categories, avoid inadvertent admissions during an inspection, and preserve defenses that are only available before a warning letter or board complaint is issued. Delaying legal representation can significantly affect the outcome of a matter and expose the provider to unnecessary risk.

How Health Law Alliance Can Help

Health Law Alliance's compounding pharmacy defense attorneys track FDA's bulks-list categories and Pharmacy Compounding Advisory Committee activity as it develops, and translate that status into a defensible compounding posture. Health Law Alliance's attorneys have overseen 2,000+ audits and handled 5,000+ matters, with 25+ years of experience. If your pharmacy or practice compounds, dispenses, or prescribes a peptide with unsettled 503A status, contact Health Law Alliance's peptide compounding attorneys for a free, confidential consultation.