Some store pages on PeptidesGrid now quote official documents that name the store's domain. Most are warning letters from the U.S. Food and Drug Administration (FDA). Here is what such a letter means, and what it doesn't. This is general information, not legal advice.
What a warning letter is
FDA's page on warning and close-out letters says: "When FDA identifies what it believes are significant violation(s) of federal requirement(s), FDA notifies the appropriate party. This notification is often in the form of a Warning Letter." The letter lists FDA's concerns and asks for a reply. A company that disagrees "has the opportunity to supply FDA with its reasoning and supporting information."
What it is not
A warning letter is not a fine or a conviction. FDA's staff manual, the Regulatory Procedures Manual, chapter 4 (July 2024), says: "A Warning Letter is informal and advisory. It communicates the agency's position on a matter, but it does not commit FDA to taking enforcement action. For these reasons, FDA does not consider Warning Letters to be final agency action on which it can be sued." It is not a court ruling either.
Why FDA writes to "research use only" sellers
Many peptide stores label their products "for research use only". FDA looks at the whole website, not just the label. Its August 24, 2026 letter to Royal Peptides LLC says: "Violations were identified and documented during a review of your website royal-peptides.com in July 2026. Based on our review, “Tirzepatide,” “Semaglutide,” “Retatrutide,” ... are unapproved new drugs under section 505(a) of the Federal Food, Drug, and Cosmetic Act (FD&C Act), 21 U.S.C. 355(a)."
A footnote in the same letter explains why the label did not settle it: "Despite statements on your product labeling marketing your products “for research use only” and “not for human or animal consumption,” evidence obtained from your website establishes that your products are intended to be drugs for human use." The letter adds that, with exceptions it says do not apply, a new drug may not be shipped between states without an FDA-approved application in effect.
What usually follows
The manual says a warning letter includes "A request for correction and a written response within a specific period of time after the date of receipt of the letter, usually fifteen (15) working days." The Royal Peptides letter asks for a reply "within fifteen (15) business days of receipt of this letter". It warns that failing to address the violations "may result in regulatory or legal action without further notice including, without limitation, seizure and injunction."
FDA's warning letters page notes: "Matters described in FDA warning letters may have been subject to subsequent interaction between FDA and the letter recipient that may have changed the regulatory status of issues discussed in the letter."
If a company fixes the problems, FDA may send a close-out letter. FDA's page says one may issue "once the Agency has completed an evaluation of corrective actions undertaken by a firm in response to a Warning Letter." A promise is not enough: "The corrective actions must actually have been made and verified by FDA." And "If the Warning Letter contains violations that by their nature are not correctable, then no close-out letter will issue." So a missing close-out does not prove that nothing has changed.
Search the letters yourself
FDA posts letters on its warning letters page. Type into the Search box above the table. Try both the domain and the company name, because letters are addressed to companies, whose names can differ from the store's. A filter can show only "Letters with Response or Closeout". Letters can appear weeks after they are sent: some posted Sep 22, 2026 were issued in June.
How PeptidesGrid shows them
- Exact domain only. A document appears on a store page only if it names that exact domain.
- Quoted, with dates. Each entry quotes the document word for word, with the date it was issued, the date the site checked it and a link to the official copy. " ... " marks words left out.
- Near misses kept off. A letter to a company with a similar name, or one naming a different domain, is not shown. A lookalike domain does not get a real store's letter, and a real store does not get a lookalike's.
- One list. The regulator actions list shows every match. On Sep 25, 2026 it held six FDA warning letters and one Justice Department case page, naming six domains.
If you run a store and think an entry is wrong or out of date, ask for a correction.
No letter does not mean safe
Most store domains on PeptidesGrid have no letter naming them. That only means none was found. FDA's manual says that "a Warning Letter is not a prerequisite to taking enforcement action" and that "FDA is under no legal obligation to warn individuals or firms that they or their products are in violation of the law before taking enforcement action, except in a few specifically defined areas." PeptidesGrid's search can also miss letters, especially older ones.
Before you pay, check the store's domain letter by letter.
FDA wording copied from fda.gov and checked Sep 26, 2026. Pages change, so read the current version. Not legal advice. Last reviewed Sep 26, 2026.