If you've been following the peptide space in 2025-2026, you've likely encountered references to "Category 1" and "Category 2" peptides. These terms come up in clinic marketing, telehealth consultations, online forums, and news coverage of regulatory changes -- but what they actually mean, and why they matter for your ability to access peptide therapies legally, is often glossed over or misrepresented.
This article breaks down the FDA's classification system for bulk drug substances used in compounding, explains what each category means in practice, and covers why reclassification has become one of the most important topics in the peptide world.
- The FDA uses a three-category system to determine which bulk drug substances can be used by compounding pharmacies.
- Category 1 can support compliant prescription compounding while FDA evaluation continues. Category 2 signals significant safety concerns. Category 3 means the substance is still under evaluation and does not qualify for Category 1 interim policy.
- These categories are about compounding eligibility, not FDA drug approval or over-the-counter access.
- BPC-157, TB-500, KPV, MOTS-c, DSIP/Emideltide, Semax, and Epitalon are scheduled for July 2026 PCAC review. That review is advisory; it is not itself approval or authorization.
Quick facts
- Category 1
- Can be compounded with a valid prescription
- Category 2
- Restricted — cannot be compounded
- Category 3
- Under active evaluation by the FDA
- Governing law
- FDCA Sections 503A and 503B
What the categories mean
The FDA maintains lists of bulk drug substances -- the raw ingredients that compounding pharmacies use to prepare medications -- organized into three categories. These categories determine whether a substance can legally be used in compounding.[1]
Category 1: May be compounded under the interim policy. These are bulk drug substances nominated with sufficient supporting information for FDA to evaluate them. FDA's current 503A policy says it generally does not intend to take action against a state-licensed pharmacy, licensed physician, or outsourcing facility solely because a Category 1 bulk substance is used, as long as the other legal conditions are met.[7] Category 1 does not mean FDA-approved, and it does not mean OTC.
Category 2: Cannot be compounded. These are substances that the FDA has determined present "demonstrable difficulties" for compounding.[2] The reasons vary: some substances were flagged for safety concerns, others for the complexity of formulating them reliably, and others because the FDA concluded there was insufficient safety or efficacy data to support their use in compounded preparations. When a substance is on Category 2, compounding pharmacies are prohibited from using it -- full stop.
Category 3: Under evaluation. These are substances that have been nominated for inclusion on the compounding lists but haven't received a final determination. The FDA is still reviewing the available evidence. A Category 3 substance could eventually move to Category 1 or Category 2 depending on the outcome of that review.[5]
How substances get categorized
The process begins with nominations. Under the framework established by the FDCA, anyone -- a physician, a compounding pharmacy, a patient advocacy group, or a pharmaceutical company -- can nominate a bulk drug substance for evaluation and potential inclusion on the 503A or 503B compounding lists.[4]
When a nomination is submitted, the FDA evaluates the substance against several criteria:[5]
- Physical and chemical characterization: Is the substance well-defined? Can its identity and purity be reliably verified?
- Safety information: What does the available evidence say about the substance's safety profile? This includes published literature, adverse event reports, and any available clinical data.
- Historical use in compounding: Has the substance been used in compounding practice, and if so, what is the track record?
- Available literature: What peer-reviewed research exists on the substance's pharmacology, toxicology, and therapeutic potential?
The FDA reviews these factors and places the substance into one of the three categories. This process is not instantaneous -- it can take months or even years, and the FDA has faced criticism for the pace at which it processes nominations.[6]
It's worth noting that the evaluation criteria are not purely scientific. The FDA also considers whether a commercially available, FDA-approved version of the substance exists (or a closely related alternative), which can influence whether compounding is deemed necessary.
Which peptides are in each category
Here's a snapshot of where notable peptides stand as of May 16, 2026. This table focuses on practical status rather than treating "Category 1" as a synonym for FDA approval.
| Peptide | Current status | Notes |
|---|---|---|
| Sermorelin | Compoundable with prescription | Established compounding pathway; not an FDA-approved currently marketed product |
| GHK-Cu | Compoundable context varies by formulation | Topical/cosmetic and compounded contexts differ; not blanket approval |
| BPC-157 | July 2026 PCAC review scheduled | BPC-157 free base and acetate are under review for potential 503A Bulks List inclusion |
| TB-500 | July 2026 PCAC review scheduled | FDA agenda evaluates thymosin beta-4/TB-500-related bulk substances |
| KPV | July 2026 PCAC review scheduled | Evaluated use on FDA agenda: ulcerative colitis |
| MOTS-c | July 2026 PCAC review scheduled | Evaluated use on FDA agenda: type 2 diabetes |
| Semax | July 2026 PCAC review scheduled | Evaluated use on FDA agenda: traumatic brain injury |
This is not an exhaustive list. The FDA's current 503A bulk-substance materials and meeting notices remain the source of record, and status can change as nominations are withdrawn, reviewed, or moved through advisory committee discussion.[7][8]
The reclassification question
The category system became front-page news in the peptide world on February 27, 2026, when HHS Secretary Robert F. Kennedy Jr. announced that his department would direct the FDA to begin reclassifying approximately 14 peptides from Category 2 to Category 1. If formalized, this would be the single largest expansion of legal peptide access through compounding in the history of the current system.
The signal was significant. Since then, FDA has scheduled a July 23-24, 2026 PCAC meeting covering BPC-157, KPV, TB-500, MOTS-c, Emideltide/DSIP, Semax, and Epitalon.[8] That is still not the same as final FDA action. Advisory review is a step in the process, not FDA approval and not OTC access.
For a reclassification to take legal effect, the FDA would typically need to conduct its own internal review, publish a proposed rule, accept public comment, and issue a final determination. That process takes time -- and the FDA's career regulatory staff have historically maintained a degree of independence from political direction.[6]
For the current meeting-specific view, see the July 2026 PCAC peptide hub. For the common BPC-157 question, see Does This Mean BPC-157 Is Legal Now?.
What this means for you
The category system has a direct, practical impact on whether you can access a given peptide through legitimate channels.
If a peptide is Category 1, a licensed prescriber can evaluate whether it's appropriate for you and write a prescription. A compounding pharmacy operating under Section 503A or 503B can then prepare it. This is the legal, regulated pathway -- and it comes with quality controls including sterility testing, potency verification, and proper labeling.[3]
If a peptide is Category 2, it is not available through legitimate compounding pharmacies. Any source offering a Category 2 peptide is operating outside the regulated system -- whether that's a gray-market research chemical vendor, an overseas supplier, or an unlicensed compounder. These sources carry documented risks including contamination, incorrect dosing, and wrong-molecule substitution.
If a peptide is on a PCAC agenda, it is being reviewed. That does not mean it is approved, OTC, legal for direct-to-consumer sale, or proven safe and effective. It means FDA is gathering advice on whether a compounding pathway should exist.
If a peptide is Category 3, its status is pending. It may become available through compounding in the future, but for now, it exists in regulatory limbo.
The most important thing you can do is stay informed. Reclassification proceedings are ongoing, and the landscape could shift meaningfully in the coming months. Work with a licensed healthcare provider who understands the regulatory environment, and verify claims about peptide legality against the FDA's official category lists rather than relying on marketing materials or social media.
References
- [1]U.S. Food and Drug Administration. “Bulk Drug Substances That Can Be Used in Compounding Under Section 503A and 503B: Category 1 List.” FDA.gov. 2024. LinkRegulatory document
- [2]U.S. Food and Drug Administration. “Bulk Drug Substances That Can Be Used in Compounding Under Section 503A and 503B: Category 2 List.” FDA.gov. 2023. LinkRegulatory document
- [3]U.S. Food and Drug Administration. “Compounding Laws and Policies: Section 503A and 503B of the Federal Food, Drug, and Cosmetic Act.” FDA.gov. 2024. LinkRegulatory guidance
- [4]U.S. Food and Drug Administration. “Bulk Drug Substance Nominations: How to Submit a Nomination for Evaluation.” FDA.gov. 2023. LinkRegulatory guidance
- [5]U.S. Food and Drug Administration. “Evaluation of Bulk Drug Substances Nominated for Use in Compounding: Criteria and Process.” FDA.gov. 2024. LinkRegulatory document
- [6]McGuire MF, Brewer JR. “Regulatory Landscape for Compounded Peptide Therapies in the United States: A Review.” Therapeutic Innovation & Regulatory Science. 2025. 59:112-124 DOIReview article
Peer-reviewed overview of FDA peptide compounding regulations and enforcement trends.
- [7]U.S. Food and Drug Administration. “Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act.” FDA.gov. 2026. LinkRegulatory document
Current FDA source for 503A bulk substance criteria and interim policy category lists.
- [8]U.S. Food and Drug Administration. “July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee.” FDA.gov. 2026. LinkRegulatory document
Official FDA meeting notice for July 2026 PCAC review of BPC-157, KPV, TB-500, MOTS-c, Emideltide/DSIP, Semax, and Epitalon.
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Disclaimer
This article reflects FDA bulk drug substance materials and PCAC notices available as of May 16, 2026. Categories are subject to change through ongoing FDA evaluation and reclassification proceedings. This is for educational purposes only and does not constitute medical or legal advice. Always consult a licensed healthcare provider before using any peptide product.