JAMA Study Finds Mounjaro More Effective For Weight Loss Than Ozempic

A new study published in JAMA Internal Medicine found that tirzepatide, the active ingredient in Mounjaro, was more effective for weight loss than semaglutide, the active ingredient in Ozempic.

Participants who were administered Mounjaro were three times more likely to lose 15 percent or more of their body weight than those who were on Ozempic.

These results were found to be robust even in the long term, as the study examined over 18,000 patients across a one-year period. Tirzepatide patients were 2.5 times as likely to achieve weight loss of 10 percent and 1.8 times as likely to experience five percent or more of weight loss, the results showed.

In examining the electronic records of more than 18,000 overweight or obese adults in the United States, the health data analytics company Truveta found that Lilly's tirzepatide helped patients lose more weight than Novo's semaglutide, with the effects growing over time.  

Additionally, patients without Type 2 diabetes lost more weight, though the reasons for these effects remain unclear. According to the study's authors, more research is needed to understand why tirzepatide is more effective for weight loss.

Semaglutide and tirzepatide belong to the weight loss drug category called glucagon-like peptide receptor agonists (GLP-1s). These medications have been prescribed for managing diabetes for quite some time, but in recent years, grew in popularity as off-label weight-loss solutions.

GLP-1s mimic a hormone in the body that regulates blood sugar and satiety and help patients lose weight by slowing gastric emptying and causing a feeling of fullness. While both Ozempic and Mounjaro are FDA-approved for diabetes management, tirzepatide is approved for weight-management purposes under the brand name Zepbound.

Prior studies found that Ozempic patients lost as much as 16 percent of their total weight, compared with more than 20 percent among Mounjaro patients. However, this newer study was the first to examine both drugs head-to-head, further supporting the notion that Mounjaro is more beneficial for weight loss.

Both semaglutide and tirzepatide are usually taken as once-weekly injections. Newer methods have emerged recently, including oral tablets and tinctures that forego the need for a painful injection.

Several side effects are possible with both classes of medications, ranging from nausea and a lack of appetite to constipation and fatigue.

Furthermore, medical professionals highly recommend cardio, strength training, and adequate amounts of protein to ensure a healthy weight-loss process. Patients commonly lost muscle mass in addition to weight, underscoring the importance of exercise and proper diet while on Ozempic or Mounjaro.

It should be noted that Novo Nordisk, the company that produces Ozempic, disputed the study's results, alleging that the head-to-head comparison was not adequately conducted.