New 'Godzilla' Weight Loss Drug More Effective Than Ozempic

In a phase 2 clinical trial, people with obesity taking retatrutide — a triple hormone receptor agonist — lost nearly one-quarter of their body weight in less than a year.

In a phase 2 clinical trial published in The New England Journal of Medicine, retatrutide, Eli Lilly's latest weight loss medication, resulted in significant weight loss in a shorter timeframe than similar drugs like Novo Nordisk's Ozempic and Lilly's own Mounjaro.

Its impressive performance has health experts calling it the "Godzilla" of injectable weight loss drugs.

Retatrutide targets three receptors — glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide 1 (GLP-1), and glucagon. In contrast, Ozempic's active ingredient, semaglutide, only activates GLP-1.

The new medication was shown to be effective in an earlier stage 1 clinical trial involving people with diabetes. In that study, participants taking the highest dose reduced their body weight by 10% in 12 weeks.

However, the stage 2 trial involved participants with obesity who did not have diabetes and found that those taking retatrutide lost a significant amount of weight in under one year.

During the trial, 324 adults with obesity and 14 adults with a high body mass index (BMI) plus at least one weight-related health condition received either a once-weekly dose of retatrutide or a placebo.

The participants also engaged in a lifestyle intervention during the study period.

People taking the highest retatrutide dose lost 18% of their body weight in 24 weeks and up to 26.8% by 48 weeks.

Moreover, some people taking the new "Godzilla" weight loss jab experienced health benefits, including lowered blood pressure and blood sugar levels.

The researchers noted that the most common side effects included nausea, diarrhea, vomiting, constipation, and skin sensitivity.

For example, in a clinical trial, people taking Ozempic (semaglutide) lost approximately 15% of their body weight over 68 weeks. Moreover, Mounjaro (tirzepatide), a medication that targets GLP-1 and GIP receptors, reduced body weight by 26.6% over 72 weeks.

Because of the promising findings, researchers will conduct a Phase 3 trial to assess the safety and efficacy of retatrutide in people with obesity, with results expected in 2026.