Eli Lilly said its next-generation obesity drug retatrutide produced much larger weight loss in a late-stage study than the company’s existing comparisons to Zepbound and Wegovy, according to an interview aired by NPR. In the program, NPR pharmaceuticals correspondent Sydney Lupkin described retatrutide as a weekly injection and said Eli Lilly presented the results from its Phase 3 clinical study as it studied the drug for potential approval.
Lupkin said retatrutide is different from current leading obesity medications in how it targets biology. She explained that Wegovy and Zepbound work on the GLP-1 hormone, while retatrutide works on three hormones—GLP-1, GIP and glucagon—and that the multi-hormone approach is part of the company’s claim that it is more powerful.
In the trial results Lupkin described, participants taking retatrutide lost an average of more than 70 pounds over 80 weeks at the highest dose, while the placebo group lost about 5 pounds over the same period. Lupkin said those were the latest findings from Eli Lilly’s Phase 3 study, and she introduced Francavilla as a physician leader to offer context on what the results could mean clinically.
Francavilla told NPR, “I have goose bumps.” She said the medical community had seen preliminary data before, adding that it was not “shocking,” but she said the level of weight loss would represent a significant shift for obesity treatment. In her view, a medication that produces an average around 28% weight loss would be “truly game-changing,” describing it as “essentially bariatric surgery but in a weekly injection.”
Lupkin and Francavilla also discussed how retatrutide’s results could compare with what patients typically achieve on existing GLP-1-based therapies. Lupkin said people taking Zepbound and Wegovy lose around 20% of their body weight over time, and she framed the retatrutide comparison as potentially getting closer to surgery levels—while noting that even medications with strong outcomes can have side effects.
On safety and tolerability, Lupkin reported that retatrutide’s side effects were similar to those seen with other GLP-1 drugs, including nausea and other gastrointestinal issues. She also asked whether that strength would translate into patients switching if the Food and Drug Administration approves it.
Francavilla cautioned that the drug would not fit everyone, and she told NPR, “You know, it won’t be for everyone.” She said the medication might be “too powerful for some people,” adding that having several obesity medications matters because clinicians would need to consider which one “makes sense for which patients.”
Lupkin said access and affordability remain major constraints even with drugs already available. She described how obesity drugs can be expensive and that many insurance plans do not cover them, even though obesity is often treated as a chronic condition.
Finally, Lupkin said retatrutide is not yet approved and that Eli Lilly has not published the Phase 3 results in a peer-reviewed journal. She reported that the company said it plans to submit retatrutide for FDA approval by the end of the year, though she said approval could take time. Lupkin also relayed Francavilla’s warning to avoid buying knock-off versions of obesity injections online, saying people “don’t know what you’re getting” and that unapproved products could be dangerous.