By Inside Your Peptides · Originally published · Language revised 2026-09-17
Lilly has reported Phase 3 results in addition to the published Phase 2 study. Retatrutide remains investigational in the US sources reviewed here; sponsor results, approval and the quality of unrelated research products are separate questions.
The evidence record has moved beyond Phase 2
Lilly's May 2026 announcement reports TRIUMPH-1 Phase 3 results. It is no longer accurate to describe the development program as still waiting for its first Phase 3 result. A sponsor announcement, a peer-reviewed publication and a regulator's decision remain different evidence sources.
Read what is being compared
Check the participant population, follow-up, comparator, endpoint and analysis approach before comparing weight-loss figures from different trials. A reported program result does not predict an individual's response or establish superiority through a cross-trial table.
Investigational does not mean approved
FDA's current public page says retatrutide is not a component of an FDA-approved drug and cannot be used in compounding under federal law. A vial marketed with the same molecule name is not the trial product, and a COA does not transfer the trial's findings to it. This page offers no personal-use or sourcing guidance.
Sources used in this revision
- Lilly · TRIUMPH-1 sponsor announcement, 21 May 2026 · Checked 17 September 2026
- FDA · Concerns with unapproved GLP-1 drugs · Checked 17 September 2026
Educational reading only. This page does not provide medical, dosing or personal-use guidance.