Lilly Says Retatrutide Beats Ozempic in 80 Week Trial

Eli Lilly reported October 28, 2026, that its experimental drug retatrutide produced substantially greater weight loss and improved blood sugar control compared with Ozempic in an 80-week clinical trial involving more than 1,000 adults with Type 2 diabetes. The findings could inform the development of next-generation treatments for diabetes and obesity, although retatrutide has not received US Food and Drug Administration approval.

According to results released by Lilly, participants receiving the 9-milligram dose of retatrutide lost an average of 44.3 pounds, while those taking the 12-milligram dose lost 47.4 pounds. Participants receiving Ozempic at its highest approved 2-milligram dose for Type 2 diabetes lost an average of 20.9 pounds over the same 80-week period.

The trial also found a greater reduction in A1C, a measure of average blood sugar levels, among participants receiving retatrutide. Lilly reported an average reduction of 2.2 percentage points with retatrutide, compared with 1.8 percentage points among those taking Ozempic.

Despite the reported benefits, retatrutide users experienced more treatment discontinuations associated with side effects. Lilly said 7.9% of participants receiving the 12-milligram dose stopped treatment because of side effects, compared with 2.7% of those taking Ozempic. Gastrointestinal problems were the most common side effects reported among retatrutide users.

Retatrutide is a once-weekly injection designed to activate three hormone receptors involved in regulating appetite, metabolism and blood sugar: GLP-1, GIP and glucagon. This combination distinguishes it from existing medications that target one or two of these hormonal pathways.

Ozempic and Wegovy, manufactured by Novo Nordisk, act on GLP-1 receptors. Eli Lilly's Mounjaro and Zepbound target both GLP-1 and GIP pathways. Retatrutide adds glucagon receptor activation, which is associated with processes involved in energy expenditure and fat metabolism.

Lilly also reported improvements in cardiovascular risk indicators, including cholesterol and blood pressure, among participants receiving retatrutide. The company did not provide specific numerical results for those measures in the reported findings.

The drug's development remains subject to regulatory review. Lilly said it plans to seek approval from the US Food and Drug Administration before the end of March 2027, following the completion of its clinical development and regulatory preparations.

Retatrutide is not yet FDA-approved, and versions advertised online may come from unregulated sources. The FDA has warned that consumers should not use unapproved versions obtained through the black market. Ozempic and Mounjaro are approved to treat Type 2 diabetes, while Wegovy and Zepbound are approved for eligible patients with overweight or obesity.