Retatrutide met primary endpoints in Phase 3 TRIUMPH-2 and TRIUMPH-3, with up to 22.6% weight loss. The triple agonist is investigational, not FDA-approved.
Eli Lilly's investigational triple agonist retatrutide met its primary endpoints in two more Phase 3 trials. TRIUMPH-2 cut body weight up to 20.8 percent in adults with type 2 diabetes, and TRIUMPH-3 cut it up to 22.6 percent in obesity with cardiovascular disease. Retatrutide is not FDA-approved; Lilly plans a 2027 filing.
On July 23, 2026, Eli Lilly reported that retatrutide, its once-weekly investigational triple agonist, succeeded in two more Phase 3 studies. TRIUMPH-2 enrolled adults with type 2 diabetes and obesity or overweight, while TRIUMPH-3 enrolled adults with severe obesity and established cardiovascular disease. Both trials met their primary weight-loss endpoints at 80 weeks. Retatrutide is not approved by the FDA for any use; it remains investigational and is available only through clinical trials.
In TRIUMPH-2, which enrolled 1,152 adults with type 2 diabetes, participants taking retatrutide lost an average of 12.7 percent (4 mg), 19.1 percent (9 mg), and 20.8 percent (12 mg) of body weight at 80 weeks, versus 4.0 percent on placebo. That translates to roughly 49.6 pounds at the highest dose. A1C, a measure of blood sugar, fell by up to 1.6 percentage points versus 0.2 for placebo.
TRIUMPH-3 enrolled 1,949 adults with a body mass index of 35 or higher and established cardiovascular disease. Participants lost an average of 21.6 percent (9 mg) and 22.6 percent (12 mg) of body weight at 80 weeks, about 55.8 pounds at the top dose, versus 3.2 percent on placebo. Lilly reported these as topline results, and full detailed data have not yet been published.
Retatrutide is a single-molecule drug that activates three gut and metabolic hormone pathways at once: GIP, GLP-1, and glucagon. Approved incretin drugs act on fewer targets. Semaglutide (Wegovy, Ozempic) is a single GLP-1 agonist, and tirzepatide (Zepbound, Mounjaro) is a dual GIP and GLP-1 agonist. Adding glucagon is intended to raise energy expenditure alongside appetite reduction.
With TRIUMPH-2 and TRIUMPH-3, retatrutide adds two more positive readouts to its Phase 3 program. The results extend its data into two harder-to-treat groups: people with type 2 diabetes, where weight loss is typically blunted, and people with obesity plus known heart disease. Even so, none of this changes its status: retatrutide is investigational and not FDA-approved, and these are company-reported topline figures, not peer-reviewed publications.
Lilly says it plans to submit a Biologics License Application to the FDA in the first quarter of 2027, so any potential approval would come later. The most common side effects across the program were gastrointestinal, including diarrhea, nausea, and constipation, consistent with other incretin drugs; discontinuation rates due to adverse events ranged from about 3.8 to 13.5 percent on retatrutide versus roughly 4.9 percent on placebo.
TRIUMPH-3 also tracked cardiovascular outcomes in people with established heart disease. The trial was not designed to prove a reduction in major adverse cardiac events, and pre-specified analyses of those events did not reach statistical significance. Consumers should also note that any product sold online as retatrutide is unapproved and unverified, and no one should start, stop, or change treatment based on trial headlines.