Retatrutide reached 22.6% weight loss in severe obesity

What happened

At 80 weeks, participants on the 12 mg dose lost an average of 55.8 lbs (22.6%) and those on 9 mg lost an average of 52.7 lbs (21.6%), versus 7.7 lbs (3.2%) on placebo.

The 12 mg dose also produced average reductions of 37.0% in triglycerides, 51.2% in hsCRP, and 9.3 mmHg in systolic blood pressure. Discontinuation due to adverse events ran 13.5% at 12 mg and 9.8% at 9 mg versus 4.8% for placebo; the most common side effects were diarrhea, nausea, constipation, and decreased appetite, generally mild to moderate. Pre-specified MACE analyses were inconclusive: time to first MACE-5 favored retatrutide (hazard ratio 0.82, CI crossing 1), while MACE-3 did not (HR 1.12).

Lilly said detailed results will be presented at future medical meetings and published in peer-reviewed journals, and it plans a Q1 2027 BLA submission. Retatrutide remains investigational and unavailable outside trials.

What it means

TRIUMPH-3 tested retatrutide in the patients who need treatment most, people already living with heart disease, and the weight-loss signal held there. Together with the other positive Phase 3 readouts, Lilly says it now has the clinical data package to support submissions for obesity, knee osteoarthritis pain, and obstructive sleep apnea.

What it does not mean

These are company-reported topline results; full publication and peer review are still ahead. The cardiovascular outcome data are not proof of heart protection, the MACE event counts were low and the confidence intervals include no effect. Earlier-phase findings, where retatrutide showed average weight loss around 24% at 48 weeks in Phase 2, were context that this trial has now extended into a Phase 3 population; they should not be read as new results here. Retatrutide cannot be legally sold or marketed for human use.