Which peptides were banned by the FDA? A guide to regulatory changes

October 12, 2025 •

3 min read

In recent years, the FDA has reclassified numerous therapeutic peptides, with a major shift in late 2023 and early 2024 that severely restricted their availability for compounding pharmacies. These actions have left many questioning which peptides were banned by the FDA and the specific reasons behind the regulatory crackdown.

Quick Summary

The FDA placed several therapeutic peptides, including BPC-157 and Thymosin Beta-4, into the Category 2 bulk drug substance list, effectively banning them from being compounded for human use due to insufficient safety data and quality concerns.

Key Points

FDA Restricted Compounding: In late 2023, the FDA reclassified numerous therapeutic peptides, moving them to the Category 2 bulk drug substance list.
Compounding Pharmacies Prohibited: As a result of the recategorification, compounding pharmacies are effectively banned from producing and distributing Category 2 peptides for human use.
BPC-157 and TB-500 Banned: Popular peptides like BPC-157 and Thymosin Beta-4 (TB-500) were specifically targeted due to insufficient human safety data and other concerns.
Safety Concerns Motivated Action: The FDA cited significant safety risks, including potential impurities, lack of clinical trials, and immunogenicity, as the basis for its decision.
Risks of Unregulated Sources: With compounded versions restricted, some consumers turn to unregulated online sources selling "research-only" peptides, which pose significant risks due to unknown quality, potency, and safety.
Some Peptides Remain Legal: Not all peptides are banned; FDA-approved versions like Semaglutide (for specific medical conditions) and some peptides for cosmetic use are still legal.

The FDA's action against compounded peptides

In September 2023, the FDA moved several peptide bulk drug substances to its Category 2 list, significantly impacting compounding pharmacies and patients. Compounding pharmacies can no longer use these substances, as the FDA cited significant safety risks including insufficient safety data, potential impurities, and adverse immune response risks. This decision has sparked debate, with some arguing it limits access to beneficial therapies, while the FDA maintains it is necessary for drug safety.

The Category 2 bulk drug substance list

FDA regulations stipulate that compounding pharmacies may only use bulk drug substances meeting specific criteria. The FDA's list categorizes substances as:

Category 1: Eligible for human compounding under certain conditions. GHK-Cu, in some forms, was added to this list.
Category 2: Ineligible for human compounding due to identified safety risks. Using these substances violates federal law.

Specific peptides moved to Category 2

In late 2023, the FDA recategorized about 17 peptides as Category 2 substances, barring their use in compounding. Key peptides included:

BPC-157: Cited for lack of human clinical data and safety concerns despite its use for tissue regeneration and gut health.
Thymosin Beta-4 (TB-500): Known for tissue regeneration, it was restricted due to concerns about impurities and immunogenicity.
Thymosin Alpha-1 (Ta1): Restricted for compounding due to safety concerns, though it was later removed for re-review in 2024.
Epitalon: Moved to Category 2, linked to longevity research.
AOD-9604: Studied for fat-loss, also placed on the restricted list.
CJC-1295 and Ipamorelin: Initially restricted growth hormone secretagogues, later removed for re-review in 2024.

Why the FDA has taken action on peptides

The FDA's actions are based on ensuring drug safety and efficacy, citing:

Insufficient human clinical trials: Much research is limited to animal or in vitro studies, lacking data for guaranteed human safety and effectiveness.
Quality control concerns: Issues with purity and impurities in bulk peptide substances used in compounding.
Immunogenicity risk: The potential for the body to develop an immune response, especially with injectables.
Potential for misuse: Concerns about peptides being used for performance enhancement.

Navigating the peptide landscape: FDA-approved vs. compounded

A comparison highlights the differences in regulatory status and availability:


Feature	FDA-Approved Peptides (e.g., Semaglutide)	Compounded Peptides (e.g., BPC-157)
Regulatory Status	Approved for specific conditions after rigorous trials and manufactured under strict oversight.	Many in Category 2, banned for human compounding due to unestablished safety and efficacy.
Legal Availability	Available by prescription.	Unlawful for compounding pharmacies; sometimes sold as "research chemicals" but warned against by the FDA for human use.
Primary Use Case	Treating type 2 diabetes, weight management (Ozempic, Wegovy).	Historically used in alternative medicine for anti-aging, tissue repair, muscle growth, and gut health.
Safety and Quality	Rigorous testing ensures consistency, purity, and safety with clear dosing and side effects.	Quality can be questionable, leading to risks from impurities, incorrect dosage, and unproven safety.

Risks of unapproved peptide sources

Following restrictions, an unregulated market has grown, with online sales of peptides labeled "for research use only" (RUO). The FDA has issued warnings against using these unapproved products for human consumption. Risks include:

Unknown quality and potency: Lack of oversight means products may not contain advertised amounts or be free of harmful impurities.
Lack of storage standards: Improper storage and shipping can compromise the stability of products, especially those needing refrigeration.
Potential for adverse events: Without clinical data, the human side effects, dosages, and long-term impacts are unknown.

Conclusion

The FDA's placement of peptides like BPC-157 and Thymosin Beta-4 on the Category 2 list restricts their use by compounding pharmacies. This is due to a lack of human safety data, quality control issues, and potential risks. While access is limited for some, the FDA prioritizes patient safety based on scientific evidence. Consumers should avoid unregulated sources and rely on FDA-approved treatments to minimize health risks.

Legal insight into peptide regulation

For more detailed legal analysis on the evolving regulatory landscape for compounded and bulk drug substances, including information on specific peptide categorizations, refer to articles from legal experts such as the Regulatory Affairs Professionals Society (RAPS).

Frequently Asked Questions

A peptide is a short chain of amino acids, the building blocks of proteins, that performs specific functions in the body. Some occur naturally, while others are synthetic.

The FDA restricted compounding of certain peptides due to concerns over insufficient safety data from human clinical trials, potential for impurities in bulk substances, and risks like adverse immune responses.

Yes, BPC-157 was placed on the Category 2 bulk drug substance list, which effectively bans compounding pharmacies from producing it for human use. The FDA cites a lack of human clinical data and safety concerns.

No. Many peptides are FDA-approved (e.g., Semaglutide) for specific medical conditions and are manufactured under strict oversight. The restrictions apply to many peptides used in compounding pharmacies, not all peptides in general.

In this context, a "banned" peptide refers to one placed on the Category 2 bulk drug list, making it ineligible for compounding by pharmacies. An "FDA-approved" peptide has undergone and passed rigorous clinical trials, proving its safety and efficacy for its specified use.

The FDA warns against purchasing "research use only" peptides for human consumption. They lack quality control and oversight, and their safety and efficacy in humans have not been established.

Peptides like BPC-157, Thymosin Beta-4 (TB-500), Epitalon, and AOD-9604 were moved to Category 2 in late 2023. Some, like CJC-1295 and Ipamorelin, were later removed for re-review.

The FDA maintains the bulk drug substance lists on its official website. The lists specify which substances are eligible (Category 1) or ineligible (Category 2) for compounding.