News explainer · Sources checked October 15, 2026
Published · Updated
Retatrutide TRANSCEND-T2D-1: the first phase 3 results
On March 19, 2026, Eli Lilly announced topline results from TRANSCEND-T2D-1, the first phase 3 trial of retatrutide, in adults with type 2 diabetes managed with diet and exercise.[1] The full results were published in The Lancet in June 2026.[2]
What the trial found
537 participants were randomized to retatrutide 4, 9, or 12 mg or placebo. At 40 weeks, HbA1c fell 1.69, 1.86, and 1.94 points versus 0.81 with placebo, and body weight fell 11.5%, 13.9%, and 15.3% versus 2.6%. Gastrointestinal events were the most frequent adverse events, and 2–5% stopped retatrutide because of adverse events. The trial was funded by Lilly.[2]
Status
Retatrutide remains investigational and is not FDA approved. Earlier phase 2 data in obesity are summarized on the retatrutide page.[3]
References
- Eli Lilly and Company. Lilly’s triple agonist retatrutide demonstrated significant reductions in A1C and weight in first Phase 3 trial for treatment of type 2 diabetes. PR Newswire, March 19, 2026. https://www.prnewswire.com/news-releases/lillys-triple-agonist-retatrutide-demonstrated-significant-reductions-in-a1c-and-weight-in-first-phase-3-trial-for-treatment-of-type-2-diabetes-302718589.html. Checked October 15, 2026.
- Bajaj HS, et al. Efficacy and safety of retatrutide in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial. Lancet. 2026;407(10546):2402-2413. PMID 42250575. https://pubmed.ncbi.nlm.nih.gov/42250575/. Checked October 15, 2026.
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. PMID 37366315. https://pubmed.ncbi.nlm.nih.gov/37366315/. Checked October 15, 2026.
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