FDA and research peptides in 2026: what the BPC-157 vote and warning letters changed

“Research peptides” sold online with a “not for human consumption” label have become a parallel market to prescription GLP-1s, and 2026 has been the year FDA’s position on them moved, twice. In April the agency took most of them off its list of substances with significant safety risks. In July its advisory committee voted to let several be compounded. And in August FDA sent warning letters to five sellers. This explainer sets out what is and is not legal as of October 14, 2026, using FDA’s own pages wherever possible.

How FDA’s compounding categories work

A 503A pharmacy can compound a drug from a bulk substance only if that substance is part of an FDA-approved drug, has a USP monograph, or is on FDA’s 503A bulks list. While it builds that list, FDA sorts nominated substances into interim categories:

FDA also said in 2025 that it does not intend to categorise substances nominated on or after January 7, 2025.

April 2026: peptides leave Category 2

In 2023 FDA placed many popular peptides in Category 2. On April 15, 2026, according to law firms Orrick and Polsinelli, FDA announced that 12 peptides would leave Category 2 after seven days because their nominators had withdrawn them. FDA’s Category 2 page, current as of April 22, 2026, now lists most of them in a separate “nominated but withdrawn” table, including BPC-157, TB-500, KPV, CJC-1295, ipamorelin, melanotan II, MOTs-C, selank, semax, epitalon, DSIP, LL-37, AOD-9604, thymosin alpha-1, dihexa and injectable GHK-Cu.

This was widely reported as a loosening, but Polsinelli’s note puts it plainly: removal from Category 2 “does not, on its own, authorize use of that substance in compounding.” A withdrawn substance is in neither Category 1 nor the bulks list. FDA’s page still says, for example, that it “lacks sufficient information to know whether” BPC-157 “would cause harm when administered to humans”.

Two substances sold as research peptides remain in 503A Category 2 on FDA’s list updated May 14, 2026: ibutamoren (MK-677, a small-molecule growth-hormone secretagogue), where FDA cites a trial stopped early over a possible congestive heart failure signal, and kisspeptin-10.

July 2026: the advisory committee votes

FDA’s Pharmacy Compounding Advisory Committee met on July 23 and 24, 2026 to consider seven peptides for the 503A bulks list. In its briefing documents FDA proposed that none be added. The committee disagreed on six. FDA has not posted the votes on its meeting page; the counts below are from McDermott Will & Schulte’s report, with the BPC-157 count confirmed by ABC’s Good Morning America.

Advisory votes are not binding. Arent Fox Schiff wrote on September 18 that “none has been added to the bulks list”, and we found no later FDA notice. The committee is due to consider GHK-Cu, dihexa, LL-37, PEG-MGF and melanotan II before the end of February 2027.

August 2026: warning letters to “research use only” sellers

On August 24, 2026 FDA sent warning letters, posted September 1, to five online sellers. Each letter quotes the seller’s “research use only” or “not for human consumption” label and concludes that the products were nonetheless intended as drugs for people.

BPC-157 was not named in the letters we read. The targets were GLP-1-type drugs and approved peptides sold outside the prescription system. FDA had already warned Gram Peptides on March 31, 2026 over retatrutide and tirzepatide labelled for research use.

FDA’s page on unapproved GLP-1 drugs, current as of October 1, 2026, is direct about two names: “Retatrutide and cagrilintide cannot be used in compounding under federal law.” Neither is part of an approved drug. Lilly reported phase 3 results for retatrutide in May 2026 and plans to file for approval in 2027; until then, any retatrutide sold online is neither approved nor lawfully compounded.

Peptides that are FDA-approved for something

A few names in the research-peptide catalogue are approved drugs, which is why FDA treats research-labelled versions as unapproved copies:

• Tesamorelin — Egrifta, approved November 10, 2010, to reduce excess abdominal fat in people with HIV-associated lipodystrophy.
• Bremelanotide (PT-141) — Vyleesi, approved June 21, 2019, for acquired generalised hypoactive sexual desire disorder in premenopausal women.
• Elamipretide (SS-31) — Forzinity, accelerated approval September 19, 2025, for Barth syndrome.
• Sermorelin — the brand Geref was discontinued; FDA has said it was not withdrawn for safety or effectiveness reasons.

How to read a peptide seller’s page

Most of the sites FDA warned in August looked like ordinary online shops. The letters show the same pattern on each: a “research use only” disclaimer at the bottom of the page, and dosing charts, before-and-after language or weight-loss claims elsewhere on the same site. FDA treated the second set of signals as evidence of intended human use. If a page tells you how many units to inject, what results to expect or how to combine a peptide with semaglutide, the disclaimer does not change what the product is.

Other warning signs: no prescription step, no named pharmacy, no lot-specific certificate of analysis, payment only by cryptocurrency or peer-to-peer apps, and product names that echo pipeline drugs, such as “GLP-3” for retatrutide. A legitimate compounded prescription comes with a prescriber, a pharmacy name on the label and a pharmacy you can look up with a state board.

What to watch next

• FDA’s decision on the July votes. FDA can accept or reject the committee’s recommendations; until it publishes a rule or list update, the six peptides stay off the bulks list.
• The next advisory meeting, due before the end of February 2027, on GHK-Cu, dihexa, LL-37, PEG-MGF and melanotan II.
• The 503B GLP-1 decision. FDA’s April 30, 2026 proposal to remove semaglutide, tirzepatide and liraglutide from the 503B bulks list was still open on October 14, 2026.
• Retatrutide’s filing. Lilly plans to file in 2027. Approval would make it a prescription drug, not a compounding ingredient.

What this means if you take a GLP-1

Peptide “stacks” are often marketed to people on semaglutide or tirzepatide for nausea, muscle or skin. None of the research peptides above is approved for those uses, and none can be legally compounded today unless it is in Category 1 or on the bulks list. NAD+ is in Category 1, and non-injectable GHK-Cu was returned to Category 1 in May 2026.

Three practical checks: buy only on a prescription that names a licensed pharmacy; treat “research use only” on anything meant for injection as a stop sign; and ask your prescriber about evidence before adding anything to a GLP-1. For the GLP-1 itself, our pharmacy profiles show each compounder’s FDA record and the 503A vs 503B guide explains the licences. We have also added an FDA-status box to each peptide reference page on this site and removed those pages from search results.

Frequently asked questions

Informational only, not medical, legal or insurance advice. Compounded drugs are not FDA-approved. Wegovy® and Ozempic® are trademarks of Novo Nordisk; Zepbound®, Mounjaro® and Foundayo™ of Eli Lilly and Company.