FDA warning letter

Peptide Partners FDA warning letter: what it says

peptide.partners · Updated 20 October 2026

On 24 August 2026 the FDA's Center for Drug Evaluation and Research sent a warning letter by email to Peptide Partners LLC, of Sarasota, Florida, about its website, peptide.partners. The letter says it follows a review of the site in July 2026.

According to the letter, the FDA considers seven of the store's products to be unapproved new drugs: semaglutide, tirzepatide and retatrutide sold under GLP names, SS-31 (elamipretide), tesamorelin, PT-141 (bremelanotide), and a reconstitution solution. It says that introducing them into interstate commerce violates the Federal Food, Drug, and Cosmetic Act.

As evidence the letter quotes the store's product pages, which summarise studies of the peptides in connection with conditions including Alzheimer's disease, diabetic kidney disease, breast cancer, retinal damage, fatty liver disease and brain cancer. It treats the reconstitution solution as a drug too, because, in the FDA's view, the store sold it to reconstitute peptides meant for injection.

The letter notes that the store labelled its products for research use only and not for human or veterinary use. It says that, despite those labels, the website shows the products are intended as drugs for human use, pointing also to bacteriostatic water sold as a solvent for the products.

The letter asks the company to reply within 15 business days of receiving it, with the steps it has taken to correct the violations it describes, or with any information showing its products are not in violation. It says that failing to address them could lead to regulatory or legal action without further notice, including seizure and injunction.

Timeline

July 2026
The FDA reviews the store's website, according to the letter.^[1]
24 August 2026
The FDA sends the warning letter by email. It names seven products as unapproved new drugs and asks for a written reply within 15 business days of receipt.^[1]
October 2026
The homepage at peptide.partners loads and shows a storefront listing peptides with prices.^[3]

What this means for buyers

A warning letter sets out the FDA's view of what it found. It is not a court ruling, and the FDA says a company that disagrees can send its reasons and supporting information.
The FDA says this letter came from a review of the store's website. The letter does not report a test of any product.
The FDA posts its warning letters on fda.gov. It may later send a close-out letter, once it has verified that a company has corrected the problems a letter raised. Check there for anything newer than this page.
This page is about the store at peptide.partners. Check the web address before you pay.
The prices below come from stores in our index. A price listing is not a test of the product.

Our directory keeps a record of this vendor: Peptide Partners.

Sources

1. Warning letter to Peptide Partners LLC (MARCS-CMS 735063). U.S. Food and Drug Administration, published 24 August 2026.Supports: The letter's date and recipient, the July 2026 review of the website, the seven products the FDA calls unapproved new drugs, the claims it quotes, its reasons for treating the reconstitution solution as a drug, its note on the store's research-use labels, the 15-business-day reply and the warning of further action.
2. About Warning and Close-Out Letters. U.S. Food and Drug Administration, published 20 March 2024.Supports: A warning letter sets out what the FDA believes are significant violations, and the recipient can answer it, including with its reasons for disagreeing. A close-out letter may follow once the FDA has verified corrections.
3. peptide.partners homepage, read by PeptidesFinder. PeptidesFinder, accessed 20 October 2026. Address: peptide.partners.Supports: The homepage loaded and showed a storefront listing peptides with prices.

Archived copies are from the Internet Archive. This page reports public records and the companies’ own statements, and claims nothing beyond them. If something here is wrong, tell us.

Current prices for these peptides

The letter names all six as products on the store's website. Below are the three cheapest retail listings in our index for each, cheapest per milligram first. Out-of-stock listings and prices under review are left out, and so is Peptide Partners.