Update, November 2, 2026. This item says retatrutide is legal only inside clinical trials. Lilly had in fact confirmed on August 3, 2026 a narrow early-access program that physicians can request for patients who cannot join a trial. Separately, the HHS peptide compounding policy published October 30 gives research-use-only products nothing: HHS says it is meant to discourage their use.
The FDA’s drug center sent warning letters dated August 24, 2026 to online sellers of injectable peptide and GLP-1 products marketed “for research use only.” The letters say the products are unapproved new drugs.
What changed. The letters, posted on FDA’s site in early September, add to a series of similar FDA letters. One letter lists products sold as “GLP-1 S (Semaglutide),” “GLP-2 T (Tirzepatide),” “GLP-3 Reta (Retatrutide),” SS-31 (elamipretide), tesamorelin and PT-141 (bremelanotide), along with bacteriostatic water for mixing them. The FDA said the website’s content made these products drugs, and that selling the water alongside them showed they were meant to be injected. Each seller was given 15 business days to respond.
What it means. The FDA continues to treat a research-only label as no defense when a website shows a product is meant for people. Nicknames such as “GLP-3” for retatrutide do not change what the product is: an unapproved substance whose contents nobody has verified.
If you take this or are considering it. Look at how the product reached you. A prescription from a clinician and a labeled product from a licensed pharmacy is one situation. A website with a research-only disclaimer, a nickname such as “GLP-3” and bacteriostatic water offered alongside is the pattern these letters describe. If you have used a product like that, tell your prescriber what it was called and how much you took, because nobody can manage a side effect from a drug they do not know you used. The letters are aimed at sellers, but the risk sits with the person holding the syringe: nobody has verified what is in the vial.
What has not changed. Approved semaglutide, tirzepatide, tesamorelin and bremelanotide products dispensed by licensed pharmacies are not affected. Retatrutide remains investigational and legal only inside clinical trials. The are peptides safe guide explains the risks of unverified products.