The short answer. Retatrutide is not FDA-approved for any use. FDA states that retatrutide cannot be used in compounding under federal law. As of September 25, 2026, Eli Lilly says it plans to file for approval in the first quarter of 2027, so there is no lawful product to prescribe today.
| FDA approved | No. Investigational. |
|---|---|
| 503A pharmacy | No pathway. FDA: “cannot be used in compounding under federal law.” |
| 503B outsourcing facility | No pathway. |
| Latest FDA action | Warning letter to Peptide Partners, Aug 24, 2026, disregarding its research-use-only label. |
| Filing timeline | Lilly plans a Biologics License Application in Q1 2027 (company statement, Aug 5, 2026). |
| MDside position | Our providers do not prescribe it. |
| Last verified | 2026-09-25 |
FDA has said it in one sentence
FDA’s page on unapproved GLP-1 drugs, updated September 1, 2026, states that retatrutide and cagrilintide cannot be used in compounding under federal law because they are not components of FDA-approved drugs. FDA has also warned active-ingredient distributors and outsourcing facilities that repackaged it.
The warning letters so far
| Date | Recipient | What FDA cited |
|---|---|---|
| Sep 9, 2025 | GLP-1 Solution | Unapproved new drug; retatrutide does not qualify under 503A or 503B. |
| Mar 31, 2026 | Gram Peptides | Retatrutide sold as “research use only.” |
| Aug 24, 2026 | Peptide Partners | Unapproved new drug; research-use-only label disregarded. |
The approval timeline, from the company itself
Lilly’s August 5, 2026 filing with the SEC says it plans to submit a Biologics License Application to FDA in the first quarter of 2027. That is a company plan. FDA review would follow, so an approved product is some way beyond that date. Earlier reports of an application in late 2026 are superseded.
What this means for you
Do not stock, prescribe or advertise retatrutide. A research-use label on the vial does not change that, and FDA’s letters say so. When patients ask for it, the conversation is about the approved options: see tirzepatide, semaglutide and our weight management program.
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Frequently asked questions
Is retatrutide FDA approved?
No. As of September 25, 2026 retatrutide is investigational. Eli Lilly says it plans to submit a Biologics License Application in the first quarter of 2027, and FDA review would follow that. There is no approved retatrutide product in the US.
Can a compounding pharmacy make retatrutide?
No. FDA states that retatrutide cannot be used in compounding under federal law, because it is not a component of an FDA-approved drug. It has no monograph and is on no bulks list, so neither 503A nor 503B applies. FDA has sent warning letters on that basis since September 2025.
What about research use only retatrutide?
FDA has disregarded that label in warning letters, including Gram Peptides in March 2026 and Peptide Partners in August 2026. A research-use label states the product is not for people. Administering it to a patient is the problem the label describes.
Primary sources. Last verified September 25, 2026. Corrections are welcome: contact us.
- FDA, Concerns with unapproved GLP-1 drugs used for weight loss (updated Sep 1, 2026)
- FDA warning letter, Gram Peptides (Mar 31, 2026)
- FDA warning letter, Peptide Partners LLC (Aug 24, 2026)
- Eli Lilly and Company, Form 8-K (Aug 5, 2026). Company statement, not an FDA document
This is general information, not legal advice. Rules vary by state and change. Confirm your own facts with counsel.