• Posted December 4, 2024

Zepbound Bests Wegovy for Weight Loss in New Trial

Zepbound, the new GLP-1 weight-loss drug from Eli Lilly & Co., has outperformed its main competitor, Wegovy, in a clinical trial funded by Lilly.

"Given the increased interest around obesity medications, we conducted this study to help health care providers and patients make informed decisions about treatment choice," Dr. Leonard Glass, senior vice president of global medical affairs at Lilly Cardiometabolic Health, said in an Eli Lilly news release announcing the trial results on Wednesday. "We are thrilled that today's findings showed the superior weight loss of Zepbound, which helped patients achieve 47% more relative weight loss compared to Wegovy."

In the study, 751 obese and overweight adults across the United States were randomized to get one of the two highest doses of either Zepbound or Wegovy. 

What did researchers discover? Patients who got weekly injections of Zepbound lost an average of 20.2% (50.3 pounds) of their body weight after 72 weeks, compared with an average of 13.7% body weight loss (33.1 pounds) for those on Wegovy.

While this is the first randomized clinical trial comparing the two rival drugs, the findings haven't yet been peer-reviewed, the company noted. Earlier research had shown Zepbound outperforms Wegovy for weight loss, but that research relied on existing data.

Still, experts say both drugs deliver impressive results.

Dr. Susan Spratt, an endocrinologist and senior medical director for the Population Health Management Office at Duke Health in North Carolina, told NBC News that although Zepbound provided more weight loss than Wegovy, both drugs work wonders.

“The amount of weight loss with both is astounding,” Spratt stressed. 

Dr. Christopher McGowan, a gastroenterologist who runs a weight-loss clinic in North Carolina, told NBC News that the side effects for both Zepbound and Wegovy are comparable, although his patients tend to say they fare better on Zepbound.

Side effects from both drugs can include abdominal pain, nausea and vomiting.

Novo Nordisk, which makes Wegovy, did not respond to requests for comment from NBC News.

Zepbound contains the active ingredient tirzepatide, the same drug used in Lilly’s diabetes drug Mounjaro. Wegovy contains semaglutide, the drug also used in Novo Nordisk’s diabetes drug Ozempic. 

Both drugs mimic a hormone that helps lowers food intake and appetite. 

However, tirzepatide imitates a second hormone called GIP, which is believed to improve how the body breaks down sugar and fat.

Spratt said she’d like to see more data comparing the drugs to health outcomes beyond weight loss. 

Wegovy, for example, has been shown to reduce the risk of heart disease in ​​people who are overweight or have obesity, she said. Meanwhile, Zepbound has been shown to be a possible treatment for obstructive sleep apnea. 

Importantly, McGowan said weight loss isn’t the only factor patients have to consider when picking a weight-loss drug.

“Most patients who seek a GLP-1 treatment choose whichever they can obtain based on cost, availability and insurance coverage,” he said. “Very few patients can be choosy right now.”

More information

Drugs.com has more on GLP-1 drugs.

SOURCE: Eli Lilly & Co., news release, Dec. 4, 2024; NBC News