FDA warning letters to peptide sellers on file
Every public FDA warning letter addressed to a storefront in the registry, newest first. For each we hold the date printed on the letter, the recipient as the record gives it, the agency's own page, and what the storefront showed on the day the file was last checked. Each letter has a page of its own; each year has a list.
By year: 2020 (1) · 2021 (1) · 2024 (3) · 2025 (1) · 2026 (1) · Download: vendors.csv · vendors.json (field trust.fda_warning_letter).
| Letter date | Recipient, as the record gives it | Products named | Storefront at last check | Letter | Pages |
|---|---|---|---|---|---|
 NuScience PeptidesNuScience Peptides LLC, Cornelius, North Carolina | 9 products | On watchlist | fda.gov ↗ | letter page · file C | |
 PureRawzPureRawz, Knoxville, Tennessee | 5 products | On watchlist | fda.gov ↗ | letter page · file F | |
| Prime PeptidesPrime Vitality, Inc. dba Prime Peptides, Santa Barbara, California | 2 products | On watchlist | fda.gov ↗ | letter page · file C | |
 Swiss ChemsSwissChems, 42 Broadway, New York | 2 products | On watchlist | fda.gov ↗ | letter page · file C | |
 Xcel PeptidesXcel Research LLC, Sheridan, Wyoming | 7 products | On watchlist | fda.gov ↗ | letter page · file F | |
 Umbrella LabsUmbrella, Tucson, Arizona | not counted in the file | On watchlist | fda.gov ↗ | letter page · file C | |
| Paradigm PeptidesParadigm R.E. LLC | one product | Closed | fda.gov ↗ | letter page · file – |
Dates are the dates printed on the letters. "Products named" is the count the record holds; the products themselves are described on the letter pages only as GLP-class products or products named in the letter. Status is what the storefront showed on the date beside it, not today.
How a letter enters a file
Desk practiceRead on fda.gov
We search the agency's warning-letter database for the company, the operator and the domain. A letter is recorded only when it is addressed to the company the file concerns. We take the date and the address of the agency's page and nothing else.
Stamped in the ledger
The "no FDA warning letter on record" check is stamped Not verified, and the seal is held at C or below for as long as the letter stands in the public record. Every other check is read as usual.
Storefront checked on a date
On the check date we record whether the storefront was reachable, closed or gated. We do not record whether the company replied to the agency; that sits on the agency's page, and we link to it.
Still trading, and not
At the last check- NuScience Peptidesnusciencepeptides.com · on watchlist · 5 of 8 checks verified · checked file
- PureRawzpurerawz.co · on watchlist · 3 of 8 checks verified · checked file
- Prime Peptidesprimepeptides.co · on watchlist · 7 of 8 checks verified · checked file
- Swiss Chemsswisschems.is · on watchlist · 7 of 8 checks verified · checked file
- Xcel Peptidesxcelpeptides.com · on watchlist · 4 of 8 checks verified · checked file
- Umbrella Labsumbrellalabs.is · on watchlist · 6 of 8 checks verified · checked file
- Paradigm Peptidesparadigmpeptides.com · storefront since closed · checked file
Reader questions
Answered from the fileWhich peptide companies got FDA warning letters in 2026?
Of the storefronts on file, NuScience Peptides (letter dated 2026-08-24). The tracker holds only letters addressed to companies the desk keeps a file on; the agency's own database at fda.gov lists every recipient.
Does "research use only" labeling protect a peptide seller from a letter?
Not in the letters on this tracker. The record notes that in 3 of the 7 letters (NuScience Peptides, PureRawz, Xcel Peptides) the agency said the research-use wording did not change how it read the products' intended use. What the labeling does and does not do is set out in the desk's explainer, linked below.
Does a warning letter close a storefront?
Not by itself. Of the 7 letters here, 6 recipients were still trading at the desk's last check and 1 had closed. A letter is an agency finding that asks for a reply; what follows is a matter between the company and the agency, and the tracker records only what the storefront showed on the check date.
The tracker is read from the same record set as every file (open data, CC BY 4.0). What a letter says in general terms is set out in What an FDA warning letter actually says; the research-use question in Research-use-only labeling explained. Every storefront listed sells material labeled for laboratory research use only. Current to ; the watchlist carries closures and unreachable storefronts alongside the letters.