Research material and lot documents.
Retatrutide trials are sponsored by Eli Lilly, and by October 15, 2026 journal papers had reported results from three phase 3 trials: TRIUMPH-1, TRIUMPH-2 and TRANSCEND-T2D-1. Each entry below gives the phase, the participants, the length and the trial ID, with the results as the authors reported them.
Phase 2, 338 adults, 48 weeks, placebo-controlled. The authors reported a mean change in body weight at 48 weeks of -8.7% to -24.2% across the retatrutide groups, against -2.1% with placebo. The most common adverse events were gastrointestinal. Source: 2023 New England Journal of Medicine, PMID 37366315.
Phase 2, 281 adults with type 2 diabetes, with placebo and dulaglutide comparison groups. At 24 weeks the authors reported HbA1c changes of -0.43% to -2.02% across the retatrutide groups, against -0.01% with placebo and -1.41% with dulaglutide. At 36 weeks body weight fell by 3.19% to 16.94% across the retatrutide groups, against 3.00% with placebo and 2.02% with dulaglutide. Source: 2023 Lancet, PMID 37385280.
A phase 2a substudy included 98 participants with metabolic dysfunction-associated steatotic liver disease and at least 10% liver fat. At 24 weeks the authors reported mean relative changes in liver fat of -42.9% to -82.4% across the retatrutide groups, against +0.3% with placebo. Source: 2024 Nature Medicine, PMID 38858523.
Phase 3, 2339 adults with obesity and no diabetes, 80 weeks, placebo-controlled. The authors reported a mean change in body weight of -17.6% to -25.0% across the retatrutide groups, against -3.9% with placebo. Among the 574 participants with knee osteoarthritis, the WOMAC pain score (1 to 10, higher is worse) changed by -3.4 to -4.1 points against -2.5 with placebo. Among the 243 participants with obstructive sleep apnea, the apnea-hypopnea index changed by -22.8 to -34.3 events per hour against -9.6. Both of these figures use the intention-to-treat estimand. The most common adverse events were gastrointestinal. Source: 2026 New England Journal of Medicine, PMID 42814954.
Phase 3, 1152 adults with obesity and type 2 diabetes at 92 centers in eight countries, 80 weeks, placebo-controlled. For the treatment-regimen estimand the authors reported a mean change in body weight of -11.9% to -18.8% across the retatrutide groups, against -5.1% with placebo. Source: 2026 Lancet, PMID 42810372.
Phase 3, 537 adults with type 2 diabetes inadequately controlled by diet and exercise, at 48 sites in the USA, Mexico and India, 40 weeks, placebo-controlled. The authors reported HbA1c changes of -1.69% to -1.94% across the retatrutide groups, against -0.81% with placebo, and mean body-weight changes of -11.5% to -15.3%, against -2.6%. Source: 2026 Lancet, PMID 42250575.
Eli Lilly has announced topline results for TRIUMPH-3 (NCT05882045, adults with severe obesity and established cardiovascular disease, 80 weeks) and TRIUMPH-4 (NCT05931367, adults with obesity or overweight and knee osteoarthritis, 68 weeks). For the efficacy estimand, Lilly reported mean body-weight changes of -21.6% to -22.6% in TRIUMPH-3, against -3.2% with placebo, and of -26.4% to -28.7% in TRIUMPH-4, against -2.1%. On October 15, 2026, PubMed searches for TRIUMPH-3 and TRIUMPH-4 with retatrutide returned only the 2026 design paper, PMID 41090431 and no results paper. Sources: Lilly news release of July 23, 2026 and Lilly news release of December 11, 2025.
These are the statuses that ClinicalTrials.gov listed on October 15, 2026. Planned enrollment is an estimate on each record.
TRIUMPH-5: retatrutide against tirzepatide in adults with obesity, 800 planned, active and not recruiting.
TRANSCEND-T2D-2: retatrutide against semaglutide in adults with type 2 diabetes, 1,250 planned, active and not recruiting.
TRANSCEND-T2D-3: type 2 diabetes with moderate or severe renal impairment, 320 planned, active and not recruiting.
TRIUMPH-6: maintenance of weight reduction, 643 planned, active and not recruiting.
TRIUMPH-7: obesity or overweight with chronic low back pain, 586 planned, active and not recruiting.
TRIUMPH-8 and TRIUMPH-9: obesity or overweight, 250 and 600 planned, active and not recruiting.
TRIUMPH-Outcomes: cardiovascular and kidney outcomes, 10,000 planned, active and not recruiting.
SYNERGY-Outcomes: liver outcomes in metabolic dysfunction-associated steatotic liver disease, retatrutide and tirzepatide, 4,500 planned, recruiting.
One trial can appear under different estimands. In TRIUMPH-2 the Lancet paper reported -18.8% for the retatrutide group with the largest change, using the treatment-regimen estimand. Lilly's July 23, 2026 news release reported -20.8% for the same group using the efficacy estimand. Its footnote says that estimand represents efficacy had all randomized participants remained on study intervention without starting prohibited weight management treatments. The placebo figure changes too: -5.1% in the paper and -4.0% in the release. Sources: PMID 42810372 and Lilly news release of July 23, 2026.
The ClinicalTrials.gov search for retatrutide lists registered studies with their sponsors, statuses and results. Check the lead sponsor on each record before relying on it. Eli Lilly and Company is the lead sponsor of every record cited on this page. The retatrutide side effects page covers the adverse events from these trials, retatrutide vs tirzepatide covers TRIUMPH-5, and the retatrutide FDA approval page gives Lilly's stated plan for an application to FDA.