New obesity drug retatrutide could rival ozempic and wegovy, early trials suggest

A new experimental weight-loss medication developed by Eli Lilly is generating attention after clinical trials suggested it could produce greater weight loss than some of today’s most widely used obesity treatments, including Ozempic, Wegovy, and Zepbound.

The investigational drug, known as Retatrutide, is still undergoing clinical testing and has not yet received regulatory approval. 

However, researchers say early results indicate it may represent the next generation of obesity medications.

Unlike current GLP-1 therapies, which target one or two hormone pathways, retatrutide is the first so-called “triple-hormone receptor agonist.” 

The once-weekly injectable medication works by targeting three hormones involved in appetite regulation, blood sugar control, fat metabolism, and energy expenditure: GLP-1, GIP, and glucagon.

Experts believe this broader mechanism may explain the drug’s striking trial results.

In a recent clinical study, participants receiving the highest dose of retatrutide lost an average of 28% of their body weight over 80 weeks. 

Nearly half of the participants lost at least 30% of their body weight, results that exceeded those reported in major trials of existing medications.

For comparison, studies of Wegovy found average weight loss of about 15%, while Zepbound produced average reductions of roughly 20% among patients on the highest doses.

Obesity medicine specialists say the findings place retatrutide in territory traditionally associated with bariatric surgery, which remains one of the most effective long-term interventions for severe obesity.

Researchers are also evaluating whether the drug may provide benefits beyond weight loss. Early studies have linked retatrutide to improvements in cholesterol levels, blood pressure, liver fat accumulation, and knee osteoarthritis symptoms. 

The medication is also being investigated as a potential treatment for conditions including sleep apnea and metabolic dysfunction-associated steatohepatitis (MASH).

Despite the encouraging data, experts caution that retatrutide remains in Phase 3 clinical trials, meaning additional research is needed to fully assess its long-term safety and effectiveness.

The most commonly reported side effects so far have been gastrointestinal issues similar to those seen with current GLP-1 medications, including nausea, diarrhea, constipation, and vomiting. 

Researchers note that reports of side effects generally increased at higher doses.

If approved, retatrutide could offer a new option for people living with obesity, particularly those who have not achieved desired results with existing medications or who have obesity-related health conditions such as type 2 diabetes, sleep apnea, or liver disease.

Health experts, however, stress that patients should avoid unapproved or counterfeit versions of the medication while clinical trials continue. They also emphasize that even the most advanced weight-loss drugs work best when combined with healthy lifestyle habits, including balanced nutrition, exercise, hydration, and long-term behavior changes.