In Study, Diabetes Drug Mounjaro Helped Dieters Shed an Average of 60 Pounds

A new trial demonstrates the power of the diabetes drug Mounjaro in fighting obesity, helping folks who used the medication lose about 60 pounds.

“In this study, people who added tirzepatide [Mounjaro] to diet and exercise saw greater, longer-lasting weight reduction than those taking placebo,” Dr. Jeff Emmick, senior vice president of product development at drug maker Eli Lilly, said in a company news release. “While intensive lifestyle intervention is an important part of obesity management, these results underscore the difficulty some people face maintaining weight loss with diet and exercise alone.”

While approved since May 2022 to treat diabetes, Mounjaro has been used “off-label” to treat obesity.

Tirzepatide works by targeting two hormones that regulate appetite and a feeling of fullness. The difference between Mounjaro and other popular weight-loss drugs like Ozempic and Wegovy is that Mounjaro targets two hormones while the others target one.

The Mounjaro study included 800 overweight and obese people who also had a weight-related health complication but did not have diabetes. Study participants weighed about 241 pounds to start and had a body-mass index of approximately 38.

More than 200 participants left trial after three months of intensive diet and exercise for varying reasons, including failure to lose weight.

Meanwhile, researchers randomized the other 600 to receive tirzepatide or a placebo via weekly injections for about 16 months.

Nearly 500 people completed the study, the researchers noted.

“This study says that if you lose weight before you start the drug, you can then add a lot more weight loss after,” lead researcher Dr. Thomas Wadden, a University of Pennsylvania obesity researcher, told the Associated Press.

Lilly presented the results Sunday at Obesity Week in Dallas, and the study was published simultaneously in the journal Nature Medicine.

“Any way you slice it, it’s a quarter of your total body weight,” Dr. Caroline Apovian, who treats obesity at Brigham and Women’s Hospital, told the AP.

People in both groups lost nearly 17 pounds during the initial phase that didn’t include the medication. That was about 7% of their body weight.

Those who then received Mounjaro lost 18.4% more of their body weight, about 44 pounds. The others regained about six pounds.

About 88% of those taking the drug lost 5% or more of their body weight during the study, compared to 17% of those on a placebo. Nearly 29% on the medication lost at least a quarter of their body weight, compared to roughly 1% of those on the placebo.

By comparison, that’s similar to results seen with bariatric surgery, Apovian said. Side effects include nausea, diarrhea and constipation, which were exacerbated as the dose was raised.

The company has been given a fast-track review of the drug to treat obesity by the U.S. Food and Drug Administration, the AP reported.

More information

The U.S. Centers for Disease Control and Prevention has more on obesity.

SOURCE: Nature Medicine, Oct. 15, 2023; Eli Lilly, news release, Oct. 15, 2023; Associated Press