Ozempic vs. Mounjaro: New study reveals which is better to combat obesity

A winner has emerged in the ongoing battle of the bulge: Mounjaro.

Overweight or obese adults are three times more likely to shed 15% of their body weight on Mounjaro than Ozempic, according to a study published Monday in the journal JAMA Internal Medicine.

“To our knowledge, this study represents the first clinical comparative effectiveness study of tirzepatide and semaglutide in adults with overweight or obesity,” researchers from the health-care analytics firm Truveta wrote in their findings.

Semaglutide, the active ingredient in Novo Nordisk’s Ozempic and Wegovy, mimics GLP-1, a hormone the body naturally produces after eating, so the user feels fuller for longer.

The US Food and Drug Administration approved Ozempic in December 2017 to treat Type 2 diabetes. The agency OK’d Wegovy in June 2021 for adult weight loss.

Tirzepatide — marketed by Lilly as Mounjaro and Zepbound — mimics GLP-1 and GIP, another appetite-suppressing hormone, which may be why it’s been shown to spur greater, sustained weight loss than semaglutide.

The FDA approved Mounjaro to treat Type 2 diabetes in May 2022 and Zepbound for adult weight loss in November 2023.

The authors of the latest study noted that patients with Type 2 diabetes tend to lose more weight with Mounjaro than Ozempic — this research focuses on adults who are overweight or obese.

The researchers analyzed the weight loss of more than 18,000 adults who took Mounjaro or Ozempic between May 2022 and September 2023.

By three months, Mounjaro patients shed 5.9% of their body weight versus 3.6% for those on Ozempic. At six months, the mean weight loss was 10.1% on Mounjaro and 5.8% on Ozempic.

At the end of the first year, Mounjaro users had dropped 15.3% of their body weight, while Ozempic patients lost 8.3%.

At the same time, the researchers didn’t notice major differences in gastrointestinal troubles — like incidences of stomach virus and swelling of the pancreas — between the Mounjaro and Ozempic groups.

The Post reached out to reps for Lilly and Novo Nordisk for comment.

In a Monday statement, Novo Nordisk pointed out that the study compares Mounjaro and Ozempic, but not Wegovy, even though weight loss was the main outcome under scrutiny. The Danish drug maker said the findings also do not provide “sufficient information” on the participants’ dosage.

“More people than ever are taking an active role in diagnosing and treating obesity, so new data is great for patients and healthcare professionals who treat them,” the statement read. “However, the ideal way to compare two treatments is an adequately powered head-to-head randomized clinical trial (RCT) in obesity. Currently, no head-to-head trials have been completed comparing tirzepatide and semaglutide 2.4 mg.”

A Lilly spokesperson says the company is studying tirzepatide and semaglutide in participants with obesity — the head-to-head trial is expected to finish later this year.

Novo Nordisk also suggested that a “significant proportion” of participants were taking Ozempic off label, because they did not have Type 2 diabetes.

The study authors reported larger weight loss in people without Type 2 diabetes than those with the chronic condition. The researchers are unsure why there was a difference but speculated it may be due to how these patients partake in other activities to lose weight.

“Additional research is needed to understand the complex relationships between motivations and outcomes for patients with and without” Type 2 diabetes, the researchers wrote.

The study authors also noted that most of the patients in their study discontinued the medicine, which affected their weight loss.

Future studies should evaluate Mounjaro and Ozempic on other key markers, such as their ability to reduce the risk of heart attacks, the study authors said.