Regulatory status of research peptides in Mexico

What does it mean for a peptide to be "for research"?

In Mexico, a research peptide is sold as a laboratory reagent (RUO, research use only). It is not a medicine: it has no COFEPRIS sanitary registration for human or veterinary use, it is not dispensed in pharmacies and it does not require a prescription, precisely because it is not sold to be administered to people. RUO labeling is not a commercial technicality; it is the product's regulatory category and defines what can and cannot legally be done with it. Since it is a domestic shipment, the order does not go through customs and is not subject to import procedures.

FDA regulatory timeline, 2023 to 2026

Much of the information circulating online about the legal status of these compounds was frozen in 2023 and is now incorrect. This is the actual sequence of decisions, with their dates:

• September 29, 2023. The FDA placed about nineteen peptides in Category 2 of the interim list of section 503A bulk substances, the category of substances that, in the agency's view, present significant safety risks. The list included BPC-157, TB-500 (thymosin beta-4 fragment), CJC-1295, ipamorelin, epitalon, MOTS-c, Semax, Selank, melanotan II and AOD-9604, among others. The practical effect was that US compounding pharmacies could no longer prepare them.
• September 2024. The FDA removed AOD-9604, CJC-1295, ipamorelin acetate, thymosin alpha-1 and Selank acetate from Category 2, after the nominations that had brought them to evaluation were withdrawn.
• January 2025. The FDA published its final interim guidance on compounding with bulk substances, which reorganized the scheme and eliminated Categories 2 and 3 as they had existed until then.
• April 2026. The FDA removed twelve peptides from Category 2, including BPC-157, TB-500 and CJC-1295. The nuance matters: removing them from that category did not move them to Category 1, nor does it amount to an authorization. They remained pending formal evaluation.
• July 23 and 24, 2026. The FDA's Pharmacy Compounding Advisory Committee (PCAC) reviewed seven peptide nominations —BPC-157, KPV, TB-500 and MOTS-c on the 23rd; emideltide (DSIP), Semax and epitalon on the 24th— and voted to recommend most of them for inclusion in the 503A list. The committee's vote is advisory: the FDA is not obliged to follow it and the final decision comes through formal rulemaking.

Status as of this review: none of these peptides is an FDA-approved medicine, none has a USP/NF monograph and the evaluation process remains open. Leaving Category 2 and receiving a favorable vote from the advisory committee are administrative steps within that process, not an authorization for use in humans.

Does removing a peptide from Category 2 mean it is now approved?

No, and it is the most widespread misunderstanding of the past year. The section 503A list governs which bulk substances US compounding pharmacies can use. Leaving Category 2 means the FDA stopped flagging that substance as a significant risk within that process: it does not move it to Category 1, it does not grant it a USP/NF monograph and, above all, it does not make it an approved medicine. Approval of a drug is a different procedure that requires complete clinical trials and a registration application. None of the peptides in this catalog has gone through it, except for molecules that already existed as medicines on their own path.

What about the molecules that are medicines, such as semaglutide?

Some molecules in the catalog also exist as approved medicines registered in Mexico, dispensed in pharmacies by prescription. Sharing a molecule does not make them equivalent. A registered medicine is manufactured under pharmaceutical standards, with stability controls, primary packaging, approved labeling and a marketing authorization holder accountable for it. A research reagent has no such backing because it is not intended for that use. Anyone seeking treatment should see a doctor and go to a pharmacy.

Competitive sport and animal research

In competitive sport, the World Anti-Doping Agency keeps substances without regulatory approval (class S0) and growth hormone-releasing factors (class S2) prohibited. Most of the peptides in this catalog fall into one of those two classes. An athlete subject to anti-doping control must check the specific compound on the current Prohibited List before any consideration.

In Mexico, animal research is subject to NOM-062-ZOO-1999 on technical specifications for the production, care and use of laboratory animals, and to the approval of the corresponding institutional committee.

Frequently asked questions