News, November 5, 2026
FDA tells Lilly retatrutide is a drug, not a biologic
FDA's Oct 2, 2026 letter says retatrutide is a drug. Lilly's appeal is pending and it plans to file by Q1 2027. Retatrutide is not FDA approved.
On October 2, 2026, FDA told Eli Lilly again that retatrutide is a drug, not a biologic [1]. FDA's rule treats a chain of more than 40 alpha amino acids as a protein, and FDA counts 39 in retatrutide [1]. Retatrutide is not FDA approved [2].
Where the case stands
The question is before the U.S. Court of Appeals for the Seventh Circuit, where oral argument was held on September 24, 2026 [3]. We found no ruling as of November 5, 2026. In an October 8 filing, Lilly said it plans to file its application no later than the first quarter of 2027 and needs to know which pathway to use [4].
Other recent news
On October 28, 2026, Lilly reported topline phase 3 results comparing retatrutide with Ozempic 2 mg in adults with type 2 diabetes [5]. These results have not yet been peer reviewed [5]. FDA says retatrutide cannot be used in compounding under federal law [2].
Sources
- FDA: Letter to Eli Lilly on retatrutide, filed in 7th Cir. No. 26-1301 (Oct 2, 2026)
- FDA: Concerns with unapproved GLP-1 drugs used for weight loss
- U.S. Department of Justice: Supplemental letter, 7th Cir. No. 26-1301 (Oct 8, 2026)
- Eli Lilly: Supplemental brief, 7th Cir. No. 26-1301 (Oct 8, 2026)
- Lilly: TRANSCEND-T2D-2 topline results (Oct 28, 2026)