Lilly's eloralintide cut weight up to 20.1% in Phase 2 trial, company reports

Eli Lilly reported on Nov. 6, 2025 that its experimental weekly injection eloralintide helped adults with obesity or extra weight lose 9.5% to 20.1% of their body weight over 48 weeks, depending on the dose, while those given a placebo lost 0.4%. The Phase 2 results were presented at ObesityWeek 2025 and published at the same time in The Lancet ^[1][2].

Eloralintide is not an incretin drug. It is a selective amylin receptor agonist, a different class from semaglutide (sold as Ozempic, Wegovy and Rybelsus) and tirzepatide (Mounjaro and Zepbound), which act on the GLP-1 and GIP hormones ^[1]. The drug, given once a week and formerly known as LY3841136, is thought to lower calorie intake mainly by affecting satiety, the feeling of fullness, according to Lilly ^[1].

Trial design and results

The 48-week study randomized 263 people in the U.S. All had obesity or overweight plus at least one related health condition, and none had type 2 diabetes ^[1]. Participants were divided among placebo, four fixed doses of eloralintide (1 mg, 3 mg, 6 mg and 9 mg) and two step-up schedules (6/9 mg and 3/6/9 mg) in a double-blind, placebo-controlled design, meaning neither the volunteers nor the researchers knew who received what ^[1][2]. Their average weight at the start was 109.1 kg, or 240.5 lbs ^[1].

Mean weight change at 48 weeks ^[1]:

• 1 mg: -9.5% (-10.2 kg; -22.5 lbs)
• 3 mg: -12.4% (-13.3 kg; -29.3 lbs)
• 6 mg: -17.6% (-18.7 kg; -41.2 lbs)
• 9 mg: -20.1% (-21.3 kg; -47.0 lbs)
• 6/9 mg step-up: -19.9% (-21.0 kg; -46.3 lbs)
• 3/6/9 mg step-up: -16.4% (-17.8 kg; -39.2 lbs)
• Placebo: -0.4% (-0.2 kg; -0.4 lbs)

Those percentages assume everyone stayed on their assigned treatment for the full 48 weeks, with pauses or dose changes allowed, which is how Lilly defines the efficacy estimand ^[1]. Lilly also notes the comparisons were not adjusted for multiplicity, a correction for running several statistical tests at once ^[1].

Side effects were mostly mild to moderate gastrointestinal symptoms and fatigue. They appeared more often at higher doses, were less common when doses were raised slowly, and showed up at rates near placebo in the 1 mg and 3 mg groups, the company said ^[1]. Lilly also reported improvements on secondary measures, including body mass index, waist circumference, blood pressure, lipid profiles, blood sugar control and markers of inflammation ^[1].

"Obesity is a complex condition, and no single treatment works for everyone," said Liana K. Billings, M.D., director of clinical and genetics research in diabetes and cardiometabolic disease at Endeavor Health in Skokie, Illinois, and the study's lead author. She said the results "suggest eloralintide could offer a promising tolerability profile without compromising on efficacy" ^[1]. Kenneth Custer, Ph.D., executive vice president and president of Lilly Cardiometabolic Health, said the drug "could serve as an alternative to incretin therapies" ^[1].

Why it matters for patients

A second way to drive weight loss could matter to people who do not handle GLP-1 medicines well, or whose progress on them has leveled off. But Lilly has not reported any trial comparing eloralintide with an approved obesity medicine, so it is not possible to say how it stacks up against semaglutide or tirzepatide ^[1]. Eloralintide is investigational and has not been approved by the FDA ^[1]. The Phase 2 study enrolled only people without type 2 diabetes; a separate Lilly Phase 2 trial (NCT06603571) is testing the drug alone and with tirzepatide in adults with obesity or overweight who have type 2 diabetes ^[1]. Whether weight stays off after treatment stops, and how the drug performs over years of use, has not been reported.

What happens next

Lilly says Phase 3 enrollment for eloralintide as a standalone obesity treatment will start by the end of the year, and a statement in the release describes enrollment beginning "next month" ^[1]. The company is also evaluating the drug as a complementary treatment alongside incretin therapy ^[1]. Dates for Phase 3 results or any regulatory filing have not been disclosed ^[1].