The TRIUMPH Trials: Retatrutide's Investigational Evidence

Part of the DietApp.com GLP-1 Trial Database, a comprehensive, regularly reviewed resource.

What It Is

TRIUMPH is the Phase 3 clinical trial program for retatrutide, Eli Lilly's investigational triple hormone receptor agonist (GLP-1, GIP, and glucagon). Retatrutide is not yet FDA-approved, and TRIUMPH is the evidence program that will determine whether and when it becomes available.

Key Results

TRIUMPH-1, the pivotal Phase 3 obesity trial, showed 28.3% average weight loss at 80 weeks in 2,339 participants, among the highest results reported for any obesity medication in development. In a 104-week extension, participants with a BMI of 35 or higher reached up to 30.3% average weight loss, with no plateau observed, meaning weight loss was still continuing at the point of measurement.

Beyond Weight Loss

A nested substudy within TRIUMPH-1 examining participants with obstructive sleep apnea found a 60.6% reduction in the apnea-hypopnea index from a severe baseline, a substantial finding given Zepbound's existing OSA approval was built on a similar mechanism-of-action premise, weight loss reducing airway obstruction.

Where the Program Stands

As of mid-2026, three Phase 3 programs under the TRIUMPH and related TRANSCEND-T2D umbrella have reported positive topline results, covering obesity and type 2 diabetes. An NDA filing is expected in late 2026, with realistic FDA approval more likely in 2027 to 2028 given the standard review timeline for a new molecule. Retatrutide remains legally available only through clinical trial enrollment until approved.

References

• Eli Lilly and Company: TRIUMPH-1 Phase 3 Topline Results (May 2026)
• Jastreboff AM et al., Retatrutide Phase 2 Data, NEJM

Related Resources

• Retatrutide Medication Guide

Related Articles

• The SURMOUNT Trials
• The SURMOUNT-OSA Trial
• Obstructive Sleep Apnea

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DietApp.com combines evidence-based GLP-1 medication education with practical treatment tracking tools. The information on DietApp.com is intended for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.

Last medically reviewed and updated: July 11, 2026.