Eli Lilly announced this week that it plans to submit retatrutide, its next-generation obesity treatment, for regulatory approval during the first quarter of 2027. The announcement follows positive results from two additional late-stage clinical trials of the weekly injectable drug.
The timeline marks a shift from the company’s earlier guidance, which suggested a filing could happen as soon as this year. Lilly told reporters the delay is needed to finish compiling and verifying the manufacturing and quality-control documentation regulators require before an application can move forward.
Strong Results Across Two Phase 3 Trials
The newly reported trials tested retatrutide in adults with obesity who also had either type 2 diabetes or established cardiovascular disease — two patient groups that often respond less well to weight-loss treatments.
- Obesity plus type 2 diabetes: Participants lost an average of up to 20.8% of their body weight — close to 50 pounds — after 80 weeks on the drug.
- Severe obesity plus cardiovascular disease (with or without diabetes): Participants lost an average of up to 22.6% of body weight, or roughly 55.8 pounds, over the same 80-week period. The trial also showed meaningful improvement in several cardiovascular risk markers.
Both studies also showed improvement in blood sugar control, and the side-effect profile was consistent with what’s already been seen in earlier retatrutide trials and in other GLP-1 class drugs — mainly gastrointestinal issues like diarrhea, nausea, and constipation.
Kenneth Custer, who leads Lilly’s Cardiometabolic Health division, said the data gives the company confidence to pursue global approval of retatrutide not just for obesity, but also for knee osteoarthritis pain and obstructive sleep apnea.
Five Successful Trials and Counting
With these two studies, retatrutide now has positive data from five separate late-stage trials. Lilly has been positioning the drug as the next major addition to its obesity lineup, joining its existing injectable Zepbound and its recently launched oral treatment, Foundayo.
Analysts are already factoring retatrutide into Lilly’s future revenue. TD Cowen projected earlier this year that the drug could generate roughly $3.8 billion in sales by 2030.
Why It Matters for the Weight-Loss Drug Race
Retatrutide is expected to play a key role in Lilly’s effort to stay ahead of Novo Nordisk in the rapidly growing obesity and diabetes drug market — a segment some analysts believe could reach roughly $100 billion in value by the 2030s.
What sets retatrutide apart is its mechanism: it targets three separate hormone pathways — GLP-1, GIP, and glucagon — earning it the nickname the “triple G” drug. Most existing treatments act on only one or two of these targets. By hitting all three, retatrutide appears to produce a stronger effect on appetite and food satisfaction than current options.
For comparison, Zepbound’s active ingredient, tirzepatide, acts on both GLP-1 and GIP, while Novo Nordisk’s Wegovy relies on semaglutide, which targets GLP-1 alone.
