The FDA 503A bulks list: how a peptide qualifies to be compounded
The official roster that decides which substances a compounding pharmacy may legally use.
TL;DR
- The 503A bulks list is the FDA's approved roster of bulk drug substances that state-licensed compounding pharmacies may use when no commercially available drug version exists.
- A substance gets on the list through a formal nomination and review process — safety, clinical need, and historical use all factor in.
- Some peptides, including BPC-157, landed on a restricted "Category 2" list pending further review; a February 2026 HHS announcement proposed returning many of them to Category 1.
What is the FDA 503A bulks list
The 503A bulks list is the official FDA roster of bulk drug substances — the raw active ingredients — that state-licensed compounding pharmacies operating under Section 503A of the Federal Food, Drug, and Cosmetic Act (FD&C Act) may use when compounding a drug product. "Compounding" here means a licensed pharmacist combining or mixing ingredients to produce a medication tailored to a specific patient's prescription.
A pharmacy may only use a bulk substance if it meets one of three conditions: it has a United States Pharmacopeia (USP) monograph (in plain English: a recognized quality standard), it is a component of an already FDA-approved drug, or it appears on the 503A bulks list. If none of those apply, the pharmacy cannot legally compound it (FDA, 2024).
How it works
Think of the bulks list like a permit board for building materials. A contractor (the pharmacy) can only use materials (bulk substances) that are on the approved list. To add a new material, someone files an application, the board reviews it, the public can comment, and then the board issues a final decision.
In practice, anyone — a clinician, a patient, or a manufacturer — may nominate a substance. The FDA then evaluates it for clinical need, safety data, and evidence of effective use. The agency publishes a proposed rule in the Federal Register (the U.S. government's official journal of regulatory actions) and accepts public comment before making a final call.
The DQSA (Drug Quality and Security Act), passed by Congress in 2013, is the law that clarified and strengthened this process. It confirmed the validity of Section 503A and created a clearer framework for how FDA evaluates bulk substances (FDA, Human Drug Compounding Laws).
Who asks about it
People come to this topic after hearing that a peptide their clinician mentioned is "not currently available from compounding pharmacies." They want to understand why — and whether the situation might change. The answer usually starts with the bulks list and the FDA's evaluation process.
What the research says
Under the FDA's former Category 1/2 interim policy framework, substances under active safety review were placed in Category 2 — meaning compounding was not permitted while review was ongoing. Several peptides, including BPC-157, were placed in Category 2 in 2023.
In January 2025, FDA published updated interim guidance in the Federal Register, announcing that the Category 1/2/3 system would no longer apply to substances nominated after that date — part of a broader modernization of the evaluation process (Federal Register, 2025).
In February 2026, HHS Secretary Robert F. Kennedy Jr. announced a proposal to move approximately 14 of the 19 Category 2 peptides back toward Category 1 availability. BPC-157 was among those named. The FDA's Pharmacy Compounding Advisory Committee was scheduled to review BPC-157 and related substances at its July 2026 meeting. Formal Federal Register notice is still required before compounding can resume.
What to know before considering it
The bulks list is not a safety endorsement. A substance on the list has cleared FDA's nomination review — it has not been evaluated in the same way as an FDA-approved drug. Access to any compounded substance requires a valid prescription from a licensed clinician, issued in states where that clinician is credentialed. Regulatory status can change; it is worth asking your provider about the current status of any specific compound.
The Halftime POV
Regulatory frameworks are not obstacles — they are the reason compounded medications can be trusted at all. The 503A bulks list exists so that patients and clinicians know the substances going into compounded preparations have been reviewed for safety. When the rules change, we share what we know.
Related reading:
- What is a 503A compounding pharmacy?
- The DQSA and FDA compounding oversight framework
- Why some peptides are still in Category 2
- 503A vs. 503B pharmacies: what's the difference?
FAQ
Q: What is the FDA 503A bulks list? A: The 503A bulks list is the FDA's official roster of bulk drug substances that state-licensed compounding pharmacies may use when no FDA-approved finished product exists. If a substance is not on this list — and has no applicable pharmacopeia monograph and is not a component of an approved drug — a 503A pharmacy cannot legally compound it.
Q: How does a peptide get on the 503A bulks list? A: Anyone — a patient, clinician, pharmacist, or manufacturer — may nominate a substance. The FDA evaluates it for safety, historical use, and clinical need, then publishes a proposed rule in the Federal Register for public comment before any final decision.
Q: Why are some peptides not allowed to be compounded? A: Under the former Category 1/2 evaluation system, substances the FDA determined may present significant safety risks were placed in Category 2 — meaning they could not be compounded while under review. BPC-157 is one example. A February 2026 HHS announcement proposed moving roughly 14 of these back toward Category 1, but formal FDA Federal Register notice is still required before compounding can resume.
Q: What is the DQSA and why does it matter for compounding? A: The DQSA (Drug Quality and Security Act) is the 2013 federal law that strengthened FDA oversight of compounding pharmacies. It clarified Section 503A — the statute that governs traditional compounding pharmacies — and created the 503B outsourcing facility category for higher-volume compounders.
Disclaimer
As of 2027-01-18, several peptides discussed in this article — including BPC-157 — 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.
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Frequently asked questions
What is the FDA 503A bulks list?
The 503A bulks list is the FDA's official roster of bulk drug substances that state-licensed compounding pharmacies may use when no FDA-approved finished product exists. If a substance is not on this list — and has no applicable pharmacopeia monograph and is not a component of an approved drug — a 503A pharmacy cannot legally compound it.
How does a peptide get on the 503A bulks list?
Anyone — a patient, clinician, pharmacist, or manufacturer — may nominate a substance. The FDA evaluates it for safety, historical use, and clinical need, then publishes a proposed rule in the Federal Register for public comment before any final decision.
Why are some peptides not allowed to be compounded?
Under the former Category 1/2 evaluation system, substances the FDA determined may present significant safety risks were placed in Category 2 — meaning they could not be compounded while under review. BPC-157 is one example. A February 2026 HHS announcement proposed moving roughly 14 of these back toward Category 1, but formal FDA Federal Register notice is still required before compounding can resume.
What is the DQSA and why does it matter for compounding?
The DQSA (Drug Quality and Security Act) is the 2013 federal law that strengthened FDA oversight of compounding pharmacies. It clarified Section 503A — the statute that governs traditional compounding pharmacies — and created the 503B outsourcing facility category for higher-volume compounders.
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