Clinical Trials
How much weight did people lose, what did TRIUMPH-4 show, how do I join a trial, and when are more results coming?
What clinical trials have been completed for retatrutide?
As of May 2026, retatrutide has completed Phase 1, Phase 2, and three Phase 3 trials with positive topline results: TRIUMPH-4 (obesity + knee osteoarthritis, December 2025, -28.7% at 12 mg/68 weeks), TRANSCEND-T2D-1 (type 2 diabetes, reported March 19, 2026 via Eli Lilly press release, HbA1c -1.7 to -2.0 percentage points and weight -11.5 to -16.8%), and TRIUMPH-1 (the pivotal obesity trial, May 21, 2026, -28.3% at 12 mg/80 weeks in 2,339 adults without diabetes, with 45.3% achieving ≥30% weight loss). The Phase 2 program included a 48-week obesity trial (NCT04881706, NEJM 2023) and a 36-week type 2 diabetes trial (NCT04867785, Lancet 2023). TRIUMPH-2 (obesity + T2D) and TRIUMPH-3 (obesity + CVD) are expected to report in the second half of 2026.
What were the main results of the Phase 2 obesity trial?
The Phase 2 obesity trial demonstrated mean weight loss of up to 24.2% at 48 weeks in the highest dose group (12 mg), with 100% of participants at that dose losing at least 5% of body weight. The trial also showed an approximately 82% relative reduction in liver fat, improvements in blood pressure and lipids, and a manageable gastrointestinal side effect profile. These were the highest weight loss results ever reported for a pharmacological agent.
What were the main results of the Phase 2 diabetes trial?
The Phase 2 type 2 diabetes trial showed HbA1c reductions of up to 2.02 percentage points at 36 weeks in the highest dose group. Approximately 95% of participants at the highest dose achieved an HbA1c below 7.0% (the standard treatment target), and approximately 62% reached HbA1c below 5.7% (the non-diabetic range). Retatrutide at higher doses significantly outperformed the active comparator, dulaglutide 1.5 mg.
What is the TRIUMPH program?
TRIUMPH (Triple Receptor Agonist Intervention Utilizing Metabolic Pathways in Health) is the Phase 3 clinical development program for retatrutide focused on obesity and weight management. It includes 4 numbered trials: TRIUMPH-1 (obesity/overweight without T2D, with nested OSA and OA baskets), TRIUMPH-2 (obesity/overweight with T2D, with nested OSA basket), TRIUMPH-3 (Class II/III obesity with established cardiovascular disease), and TRIUMPH-4 (obesity with knee osteoarthritis, completed December 2025). TRIUMPH-Outcomes is a separate 10,000-patient cardiovascular outcomes trial. The separate TRANSCEND program addresses the standalone T2D indication.
When will Phase 3 results be available?
TRIUMPH-4 reported in December 2025, TRANSCEND-T2D-1 on March 19, 2026, and TRIUMPH-1 on May 21, 2026 — three positive pivotal readouts now in hand. The remaining major readouts are TRIUMPH-2 (obesity + type 2 diabetes) expected Q2-Q3 2026, and TRIUMPH-3 (obesity + established cardiovascular disease) expected Q3-Q4 2026. Per Eli Lilly's Q1 2026 earnings call (April 30, 2026), the company maintained guidance for NDA submission in late 2026 to Q1 2027.
Can I participate in a retatrutide clinical trial?
This resource does not facilitate clinical trial enrollment. If you are interested in participating in a clinical trial, discuss this with your healthcare provider or search for registered studies on ClinicalTrials.gov using the search term 'retatrutide' or 'LY3437943'. Eligibility criteria vary by trial and are determined by the study investigators.