Category 1 vs Category 2 peptides: the access framework
Not all peptides have the same legal access path. The FDA’s compounding framework creates three distinct lanes — and knowing which lane a peptide is in tells you a lot about what’s available and what isn’t.
TL;DR
- The FDA’s 503A compounding framework includes a “Bulk Drug Substances” list that determines which compounds can be used by state-licensed compounding pharmacies — peptides not on this list cannot legally be compounded.
- Category 1 peptides are eligible for compounding under current interim policy; Category 2 peptides have been placed under heightened FDA scrutiny due to identified safety questions and are not currently eligible.
- In February 2026, HHS announced a proposal to return seven Category 2 peptides to Category 1 — but this is pending formal FDA Federal Register notice and is not yet effective.
What it is
Under Section 503A of the Federal Food, Drug, and Cosmetic Act, state-licensed compounding pharmacies may prepare customized medications for individual patients — but only using ingredients that appear on the FDA’s approved Bulk Drug Substances (BDS) list, or meet other specific criteria. For peptides, the FDA has been working through a multi-year evaluation process to determine which compounds belong on this list. The terms “Category 1” and “Category 2” emerged from this process as shorthand for the FDA’s interim access determinations.
How it works
The FDA’s Pharmacy Compounding Advisory Committee (PCAC) evaluates nominated bulk drug substances and provides recommendations to the agency. Based on this process, peptides were sorted into categories reflecting the FDA’s current assessment of available safety and efficacy data. Category 1 designation indicates the FDA has determined, under its interim policy, that the substance may be used in 503A compounding. Category 2 designation indicates the FDA has identified significant safety concerns — or insufficient human safety data — that preclude interim eligibility for compounding. The PCAC voted in 2023 to place 19 peptides in Category 2. A separate February 2026 HHS announcement proposed reconsidering seven of those placements, but as of publication date, that proposal has not become effective through the required Federal Register rulemaking process.
Who asks about it
People come to this topic when they’ve heard about specific peptides — often BPC-157 or TB-500 — and want to understand why they can’t be prescribed through a licensed clinic. The Category 1 / Category 2 framework is the answer: it’s not that these compounds are banned outright, it’s that the FDA’s compounding access pathway is closed to them until either the rulemaking changes or additional safety data is evaluated.
What the research says
The FDA’s PCAC process is documented through publicly available meeting minutes and Federal Register notices. The 2023 PCAC vote placed 19 peptides in Category 2 based on the committee’s review of available safety data — or the lack thereof. The committee’s concern was not typically that the peptides were known to be harmful, but that the human safety data to support 503A eligibility had not been established to the required standard. The February 2026 HHS announcement proposing reclassification of seven peptides cited emerging data and policy reconsideration — but the announcement itself is not the legal change. That requires formal Federal Register publication and a comment period.
What to know before considering it
Category 2 peptides are not available from state-licensed 503A compounding pharmacies under current policy. Any product marketed as a Category 2 peptide for human use outside this framework does not carry the legal and quality-control safeguards of licensed compounding. Halftime Health only provides therapies through licensed clinicians using legally eligible compounded or FDA-approved products. The reclassification process should be monitored at FDA.gov for updates.
The Halftime POV
The regulatory framework is genuinely complex, and that complexity exists for a reason — it’s the mechanism by which patient safety is evaluated before a compound enters widespread clinical use. We think the most useful thing we can do is explain how this framework actually works, without either dismissing it or catastrophizing it. Understanding the categories makes you a better-informed participant in the conversation about which therapies are appropriate and available now.
Related reading:
FAQ
Q: What is the FDA’s Category 1 vs Category 2 peptide classification? A: The FDA evaluates bulk drug substances nominated for compounding under 503A pharmacies. Category 1 peptides have been reviewed and found to meet the criteria for inclusion — they can be legally compounded and dispensed. Category 2 peptides have been reviewed and found to lack adequate clinical evidence or present safety concerns — they cannot be legally compounded under 503A.
Q: Which peptides are currently Category 1? A: Day-1 compounds at Halftime Health — including sermorelin, CJC-1295, ipamorelin, tesamorelin, thymosin alpha-1, GHK-Cu, PT-141, and oxytocin — are Category 1 and available through licensed 503A pharmacies. The FDA maintains a current list at FDA.gov; always verify current status, as it can change.
Q: What is the path from Category 2 back to Category 1? A: A compound can return to Category 1 through formal FDA Federal Register notice following a review process. The February 2026 HHS announcement expressed intent to return several peptides, but this is a preliminary step — the formal administrative process requires Federal Register publication, comment period, and final agency action. Until that notice is published, Category 2 status applies.
Disclaimer
As of April 2026, several peptides discussed in this article — including BPC-157, TB-500, KPV, MOTS-c, DSIP, epitalon, and Semax — are classified by the FDA as Category 2, which means they are not currently available from 503A compounding pharmacies. A February 2026 HHS announcement proposed returning these peptides to Category 1 pending formal FDA Federal Register notice. This article is educational and is not medical advice. Halftime Health only prescribes through licensed clinicians in states where our partner physicians are credentialed.
Get updates
Halftime Health is launching soon. We’ll share what we learn along the way — the research, the regulations, the real-world trade-offs. Join the waitlist and we’ll email you when we’re live.
Sources
- FDA. “Bulk Drug Substances That May Be Used in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act.” FDA.gov
- FDA. PCAC Meeting Materials, 2023. FDA.gov
- HHS Press Release. February 2026 peptide reclassification announcement. HHS.gov
