TRIUMPH-2 Found 20.8% Weight Loss With Retatrutide—but No Proof Yet of Fewer Heart Events

TRIUMPH-2, a Phase 3 trial in adults with type 2 diabetes and obesity or overweight, found that once-weekly retatrutide produced substantial weight loss and improved blood-sugar control over 80 weeks. At the 12 mg dose, average weight loss was 20.8%, compared with 4.0% with placebo. The cardiovascular findings were improvements in risk factors—not proof that the drug prevents heart attacks or strokes. 458

What TRIUMPH-2 found after 80 weeks

At 12 mg, participants lost an average of 49.6 pounds (20.8%) of their starting body weight. Average losses at 4 mg and 9 mg were 12.7% and 19.1%, respectively; the placebo group lost 4.0%. 8

Results were also substantial among participants who began with a BMI of at least 35: those taking 12 mg lost an average of 60.8 pounds, or 23.4% of their body weight. By the end of the study, 59.5% of participants in the 12 mg group no longer met the BMI criteria for obesity. 5

Blood-sugar control improved too. Retatrutide lowered HbA1c—the measure of average blood glucose—by up to an average of 1.6 percentage points. 19

Cardiovascular risk factors improved, but outcomes remain unproven

The reported results included favorable changes in cardiovascular risk factors such as blood pressure and blood lipids. Those measurements can inform a picture of cardiometabolic health, but TRIUMPH-2’s findings do not establish that retatrutide reduces heart attacks, strokes or cardiovascular deaths. 3437

That distinction matters when comparing medicines. Retatrutide acts on GLP-1, GIP and glucagon receptors. TRIUMPH-2 compared retatrutide doses with placebo; it was not a head-to-head trial against semaglutide or tirzepatide. So its weight-loss result cannot show that retatrutide works better than either drug. 348

Side effects and treatment discontinuation

Gastrointestinal effects—including nausea, vomiting and diarrhea—were among the most frequently reported adverse events. 9

The share of participants who discontinued treatment because of adverse events was 3.8% in the 4 mg group, 11.6% in the 9 mg group and 7.7% in the 12 mg group, compared with 4.9% with placebo. 6

What comes next—and what is not established

Lilly has said it plans to submit a Biologics License Application to the FDA in the first quarter of 2027. TRIUMPH-2 is part of a wider Phase 3 program studying retatrutide. The drug remains investigational. 11238

The available sources do not establish a specific Lilly plan for legal or regulatory action against unauthorized copycat products. Trial results describe the studied medicine and should not be taken as evidence about products sold outside the clinical-trial program.