"Turbocharged" New Weight-Loss Drug Has Patients Losing 24% of Body Weight

injecting weight-loss drug to stomach — PeopleImages.com - Yuri A / Shutterstock

In the ever-growing world of weight-loss drugs, Novo Nordisk's Ozempic stands out from the crowd (even though it's only FDA-approved for type 2 diabetes). People taking Ozempic and its sister weight-loss drug, Wegovy, have dropped massive amounts of weight, but these big names aren't the only treatment options. Eli Lilly is now developing another drug, retatrutide, and the latest data suggests it may be even more effective for weight loss.

Impressive results were presented at the 2024 European Congress on Obesity (ECO) in Venice, Italy, this week. Researchers studied 338 adults who had a body mass index (BMI) of 30 or higher—meaning they were considered obese—with a weight-related condition other than type 2 diabetes. They were given 1-milligram, 4-milligram, 8-milligram, or 12-milligram doses of retatrutide or placebo weekly.

At the halfway point of the study, people taking the highest dose of retatrutide (12 mg) lost an average of 17.5 percent of their body weight. After 48 weeks, patients on the 12-mg dose lost a whopping 24.2 percent of their body weight. Even more staggering, a quarter of these participants lost 30 percent or more of their baseline body weight. For comparison, those who took a placebo only lost 1.6 percent of their body weight at 24 weeks and 2.1 percent at 48 weeks.

Women saw a higher percentage of weight loss on retatrutide when compared to men (26.6 percent versus 21.9 percent, respectively), as did people with BMIs of 35 or higher. But beyond weight loss, patients taking retatrutide also saw improvements in waist circumference, blood sugar levels, lipid levels, and blood pressure measurements.

The study was first published in the New England Journal of Medicine (NEJM) last June, but researchers shared their thoughts on the results at the ECO conference.

'The results are striking. In a phase two trial, this degree of weight reduction in this time frame has not been seen," lead study author Aria Jastreboff, MD, PhD, associate professor of medicine and director of the Yale Obesity Research Center, said, per the Daily Mail.

Wondering what sets this drug apart from its competitors? The difference is in the hormone receptors it targets.

Ozempic and Wegovy, which have the active ingredient semaglutide, are glucagon-like peptide-1 agonists. Semaglutide mimics the hormone receptors to control blood sugar and make you feel fuller longer. Mounjaro and Zepbound, which contain tirzepatide, activate the GLP-1 hormone receptor as well as glucose-dependent insulinotropic polypeptide (GIP) to accomplish the same thing.

Retatrutide takes things a step further, targeting three hormone receptors: GIP, GLP-1, and glucagon receptors. Glucagon receptors are involved in blood sugar management and help the body burn fat with movement.

"It is basically Mounjaro but turbocharged," Alex Miras, clinical professor of medicine at Ulster University in Northern Ireland, told the Daily Mail. "What glucagon does is it increases energy expenditure—so the amount of energy that you burn. So there are two mechanisms; decreasing food intake and increasing energy expenditure. Up until now all of the medications have just focused on reducing food intake."

Adverse events with retatrutide were similar to those seen with existing weight-loss drugs. Patients reported gastrointestinal (GI) issues, namely nausea, diarrhea, and vomiting, which were mild to moderate in severity. These mainly occurred during dose escalation, when patients gradually increased the amount of retatrutide they were injecting each week to improve tolerability.

Still, medical professionals say that retatrutide could have even more significant weight-loss results over longer periods—but larger studies will be needed to determine safety.

"The trial suggests retatrutide still hadn't plateaued, so it's probably going to see more weight loss. If we give this drug for even longer I think it could reach nearly 30 percent of someone's body weight," Naveed Sattar, a professor of cardiometabolic medicine at Glasgow University, told the Daily Mail.

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Abby Reinhard Abby Reinhard is a Senior Editor at Best Life, covering daily news and keeping readers up to date on the latest style advice, travel destinations, and Hollywood happenings.Read moreFiled UnderMedicine • News • Science • Weight LossSources referenced in this article