FDA Warning Letters on Peptides: A Running Tracker

What happened / Why it matters

What happened. Since January 2025, FDA has posted at least 149 warning letters that name a peptide drug, according to FDA’s published letters: 72 dated 2025 and 77 dated 2026 so far. The latest we found is dated Oct. 30, 2026. This page lists them by category, with what FDA cited and a link to each letter on fda.gov.

Why it matters. Warning letters are one of the clearest public signals of how FDA reads the rules for sellers, pharmacies, telehealth companies and manufacturers of peptide drugs. They are also easy to misread. Each one is FDA’s position on specific facts at its date. None is a court ruling or a penalty. This tracker states what the letters say and nothing more.

How to read this tracker

• Everything here is attributed to FDA. “FDA said” means the letter says it. We do not characterize the companies, and we do not name them: each row links to the letter itself.
• A letter is not a ruling. It states findings and invites a response. We have not checked responses, closures or any later action.
• A product is not a molecule. Semaglutide, tirzepatide, liraglutide, tesamorelin and bremelanotide have FDA-approved products. When FDA calls something an “unapproved new drug,” it is talking about that company’s product, not saying the molecule itself is unapproved.
• The list may be incomplete. FDA’s search may not index every letter, and some are posted weeks after their date. Treat the counts as “at least.”
• Dates are the letters’ issue dates.

“Research peptide” sellers

On Aug. 24, 2026, FDA issued five letters to sellers of products labeled for research use, and on March 31, 2026 it issued five more. In the letters we read, FDA said “research use only” and similar labels did not change its conclusion, because evidence on the sellers’ websites established that the products were intended for human use. Our analysis of those letters explains the reasoning and what a letter does not prove.

Compounding pharmacies, repackagers and manufacturers (after inspections)

These letters followed FDA inspections of facilities that make or repackage compounded drugs.

Active ingredient manufacturers and distributors

Online pharmacies

Holders of approved products

These letters went to companies that hold approved applications for products with these active ingredients.

Telehealth companies promoting compounded GLP-1 drugs

FDA has sent 111 letters to telehealth companies since September 2025, in four groups. The letters most often say that a company’s claims implied its compounded product is the same as an FDA-approved product, or has been FDA-approved or otherwise evaluated for safety and effectiveness, when it has not, or that claims about compounded semaglutide and tirzepatide are false or misleading. FDA’s page for telehealth companies says that promoting compounded drugs with false or misleading claims “violates federal law” and that FDA does not approve or license pharmacy facilities.

We list the telehealth group by date rather than letter by letter. Every letter is on FDA’s warning letters page.

What is not in this tracker

• Letters that matched our searches but do not cite a peptide drug, such as a supplement ingredient or a cosmetic. We left five of those out.
• Import alerts, recalls and consumer notices.
• Letters FDA closed without a published letter, and any response or closure letter after a warning.
• Letters from before Jan. 1, 2025.

What this means for a reader

• A warning letter says something about a company’s conduct or product, not about whether you can safely use a particular medicine. Compounded drugs are not FDA-approved, and FDA does not review compounded drugs for safety, effectiveness or quality before they are marketed.
• For questions about a medicine you take or are considering, talk with a licensed clinician. FDA’s MedWatch program takes reports of serious reactions.
• We do not link to sellers or give dosing, preparation or purchasing guidance.

U.S. regulatory status checked Nov. 3, 2026. We update this page when we find new letters; changes are noted with a visible date.