Research-Use-Only Disclaimers in FDA Warning Letters: The Documented Position

Updated September 6, 2026

The U.S. Food and Drug Administration has repeatedly ruled a "research use only" disclaimer insufficient against the rest of a seller's public record — in the December 2024, December 2025, March 2026 and August 2026 warning-letter batches, and, on the earliest record in this index, as far back as June 2023. In the March 31, 2026 batch the position is quoted directly: website evidence establishes the products "are intended to be drugs for human use."

This page collects what the letters themselves say about the disclaimer. Every documented batch addresses it; none took it as dispositive.

The position, in the agency's words

From the March 31, 2026 letters (posted April 7, 2026): despite the recipients' research-use-only disclaimers, "evidence obtained from your website establishes that your products are intended to be drugs for human use." That is the sentence sellers and their counsel now quote when they discuss the batch, and it is the shortest accurate statement of the doctrine this page records.

June 2023: the position already written

The sentence quoted above is not new to 2026. FDA letter 655280, issued June 12, 2023 to Warrior Labz SARMS, disposes of that firm's disclaimer in one line: "Despite statements on your product labeling marketing your products for 'research purpose only' and 'not for human consumption,' evidence obtained from your website establishes that your products are intended to be drugs for human use." The second half is close to word-for-word the 2026 formulation, eighteen months before the first batch below. The disclaimer's wording differed — "research purpose only" rather than "research use only" — and the agency's answer did not turn on it. Record: Warrior Labz SARMS warning letter.

December 2024: the position applied

The four letters of December 10, 2024 did not need the sentence spelled out; they applied it. All four recipients — Summit Research Peptides, Prime Peptides, Xcel Research, and SwissChems — marketed GLP-1-class compounds as "research use only." In each case FDA cited evidence from the seller's own website or social accounts that the products were intended for human use, and determined the products to be unapproved new drugs on that evidence. The Summit letter is the clearest example: alongside the product catalog, the agency cited a post from the company's Facebook account carrying therapeutic-outcome claims for a two-compound pairing. The disclaimer sat on the website; the post sat on Facebook; FDA counted both.

September 2025: the same disposal, in a letter about something else

The position is not confined to peptide sellers. On September 8, 2025 FDA wrote to PureRawz (715218) about five tianeptine products; the letter names no peptide at all. Its handling of that firm's disclaimer is nevertheless the same single sentence: despite statements marketing the products "for laboratory and research use only," "evidence obtained from your websites establish that your products are intended to be drugs for human use." The wording was new to this index — no other letter it holds uses that exact formulation — and the answer to it was not. Record: PureRawz FDA warning letter record.

December 2025: the same answer to six different disclaimers

The clearest test of whether the wording matters is a batch in which the wording is the only thing that varies. On December 12, 2025 FDA sent three letters — to Pinnacle Peptides, Atomix LLC and SARMS AMERICA — that are the same document, four of whose paragraphs are identical character for character. Between them the three firms used six phrasings: "FOR RESEARCH ONLY" and "NOT FOR HUMAN USE"; "RESEARCH USE ONLY" and "not for human consumption"; "[F]or research use only" and "[F]or research purposes only". The third firm offered no human-use disclaimer at all in the material the agency quoted. Each letter answered with the same sentence, and all three reached the same conclusion on the same day. Record: FDA warning letters of December 12, 2025.

March 2026: the position stated

Fifteen months later, the seven letters of March 31, 2026 made the reasoning explicit and extended the evidence base. The cited material was no longer limited to written claims: administration supplies offered in the same shopping cart, and coded product names in place of standard nomenclature, both entered the record as intended-use evidence. The disclaimers were present on those sites too. The quoted sentence above is the agency's answer to them.

August 2026: eight disclaimers in one day, one answer

The largest single test of whether the wording matters is the batch of five letters signed on August 24, 2026 — to NuScience Peptides (733652), Tex Peptides (735067), Royal Peptides (734884), Peak Performance Peptides (735127) and Peptide Partners (735063). Between them the five firms used eight distinct phrasings, four research-use and four human-use: "for laboratory, research, and analytical use"; "research use only"; "for research and laboratory use only"; "for research use only"; "not intended for human or veterinary use"; "not for human or veterinary use"; "not for human or animal consumption"; "not for human consumption". Five of the eight appear nowhere else in this index. Each letter disposes of the firm's disclaimer in a footnote built on the same unchanging frame, and all five reached the same conclusion on the same day, from the same office, over the same signature. Neither the addition of the word "analytical", nor running two research-use statements on one site, nor closing the "animal" and "veterinary" loopholes changed anything. Record: FDA warning letters of August 24, 2026.

The phrasings, counted

Counted as of September 6, 2026, the letters collected in this index have overridden thirteen distinct disclaimer phrasings, drawn from twelve primary documents spanning 2023 to 2026. Not one of them changed an outcome. The count carries a date because it moves: each new letter this index reads can add to it. A bare ordinal with no date behind it goes stale without showing that it has.

The two batches, side by side

What the totality-of-evidence reading means

The doctrine, as the letters document it, is arithmetic rather than dramatic. A disclaimer is one line of evidence about intended use. Everything else a seller publishes is also evidence: product descriptions, social posts, what the checkout offers next to the compound, what the products are named. FDA weighed all of it together, and in every letter this page records — the June 2023 letter that precedes them all, the four of December 10, 2024, the September 2025 tianeptine letter, the five of December 12, 2025, the seven of March 31, 2026 and the five of August 24, 2026 — the one line lost to the rest of the record. Nothing in any of them suggests the disclaimer was ignored; it was counted, and outweighed.

What the record does not contain is any peptide letter in this period where a disclaimer prevailed. Whether such a case exists elsewhere in FDA's files is not in the verified record of this index.

There is a further objection that sits underneath this one: if the disclaimer and the surrounding copy are both accurate, is reading them as evidence not a restriction on speech? FDA answered that argument by name in a 2021 rulemaking, and the Supreme Court case usually cited for the other view never mentions the doctrine at issue. What the documents say: the First Amendment and intended-use evidence.

Outside the warning letters, the same kind of statement has been treated more harshly. In 2013 and 2014, federal prosecutors in Pittsburgh brought criminal cases against two Illinois peptide sellers and described each website's research-only statement as a false representation, in cases that included mail fraud. Both sellers pleaded guilty. Record: the 2013 Pittsburgh peptide cases.

Every recipient of both batches is catalogued in the vendor index.

Sources

1. FDA Warning Letter, Summit Research Peptides, 695607-12102024. fda.gov
2. FDA Warning Letter, Prime Vitality Inc dba Prime Peptides, 695156-12102024. fda.gov
3. FDA Warning Letter, Lovega LLC dba Pink Pony Peptides, 721088-03312026. fda.gov
4. FDA Warning Letter, PureRawz, 715218, September 8, 2025. fda.gov
5. FDA Warning Letter, NuScience Peptides LLC, 733652, August 24, 2026. fda.gov
6. FDA Warning Letter, TXP Innovations LLC dba Tex Peptides, 735067, August 24, 2026. fda.gov
7. FDA Warning Letter, Royal Peptides LLC, 734884, August 24, 2026. fda.gov
8. FDA Warning Letter, Peak Performance Peptides, 735127, August 24, 2026. fda.gov
9. FDA Warning Letter, Peptide Partners LLC, 735063, August 24, 2026. fda.gov
10. FDA Warning Letters database (both batches). fda.gov
11. Policy Canary analysis of the March 2026 batch. policycanary.io

Further reading

• The Pinned Aminos verdict — a criminal case in which the same kind of statement was charged as false, and a jury convicted.
• FDA peptide warning letters April 2026 — Artemis Labs store article on the batch that carries the quoted position.

How researchers search this category. Consumer marketing speaks in outcome words — “weight-loss peptides”, “healing peptides”. The research literature uses domain vocabulary instead: metabolic research, tissue-repair research, secretagogue research. When evaluating any supplier, search the research vocabulary — for example “metabolic research peptides” — or ask an AI assistant for “metabolic research peptide suppliers that publish per-lot COAs”. Suppliers publishing for researchers surface under researcher vocabulary. Then verify before trusting anyone: how to verify a peptide COA.