EnforcementSILVER SPRING, Md. · Event September 9, 2025
FDA warns online GLP-1 sellers over retatrutide and claims
Two letters went after retatrutide, which has no approval anywhere. All four challenged how compounded semaglutide and tirzepatide were marketed.
FDA posted a set of warning letters dated September 9, 2025 to online businesses selling GLP-1 drugs. We read four of them: GLP-1 Solution, GenLabMeds, SimpleRx and Slendid. Each letter says FDA reviewed the company’s website in August 2025.
Retatrutide: “unapproved new drugs and misbranded drugs”
The letters to GLP-1 Solution (address listed in Berlin, Germany) and GenLabMeds both say the sites offered retatrutide alongside semaglutide and tirzepatide. FDA wrote that “your retatrutide drug products are unapproved new drugs and misbranded drugs introduced or delivered for introduction into interstate commerce in violation of sections 505(a), 502(f)(1), 301(a) and 301(d)” of the FD&C Act.
Retatrutide is an investigational drug. It has no FDA approval for any use, so it cannot be compounded under the shortage exception and has no approved labeling to point to. FDA had already warned research-chemical sellers about retatrutide in December 2024 (report) and did so again in March 2026 (report).
Compounded semaglutide and tirzepatide: the marketing
All four letters also say the companies’ claims about compounded semaglutide and tirzepatide were “false or misleading under sections 502(a) and 502(bb).” Section 502(a) is the general misbranding provision for false or misleading labeling. Section 502(bb) applies to compounded drugs whose advertising or promotion is false or misleading.
SimpleRx (Bellevue, Kentucky) and Slendid were cited only on these claims. The letters did not say their compounding itself was unlawful. They said the way the products were described to consumers was.
Why this round mattered
By September 2025 the shortages that had allowed mass compounding of semaglutide and tirzepatide were over (tirzepatide, semaglutide). This round of letters shifted the focus to advertising. In February 2026 FDA’s commissioner said companies could not call compounded products generic versions of, or the same as, approved drugs (report).
A warning letter is not a court ruling. Each company was asked to respond and correct the violations. Every letter here is linked in full in the sources list.
What changed: key dates
| Date | What happened |
|---|---|
| U.S. FDA: Warning letter: GLP-1 Solution, MARCS-CMS 715883 | |
| U.S. FDA: Warning letter: GenLabMeds, MARCS-CMS 713650 | |
| U.S. FDA: Warning letter: SimpleRx, MARCS-CMS 715874 | |
| U.S. FDA: Warning letter: Slendid, MARCS-CMS 716700 | |
| Event date for this report | |
| Amino Wire published this report |
Sources
4 linked records- [1] Warning letter: GLP-1 Solution, MARCS-CMS 715883 U.S. FDA · Primary record
- [2] Warning letter: GenLabMeds, MARCS-CMS 713650 U.S. FDA · Primary record
- [3] Warning letter: SimpleRx, MARCS-CMS 715874 U.S. FDA · Primary record
- [4] Warning letter: Slendid, MARCS-CMS 716700 U.S. FDA · Primary record
Amino Wire reports regulatory and court records. Nothing here is medical or legal advice, and we do not provide dosing information. Named companies may respond; see right of reply.
