Diabetes medication Mounjaro is more effective than Ozempic for weight loss, study says

The research included more than 18,000 patients who took the drugs over the course of a year

Ozempic competitor Mounjaro was more effective at promoting weight loss in a new study conducted by Truveta.
Josh Morgan/USA TODAY NETWORK

Both Mounjaro and Ozempic are weekly, injectable diabetes drugs that have become enormously popular for their touted weight loss benefits. But according to new research, one works better than the other at reducing body weight.

The health system collective Truveta found that tirzepatide, which is sold under the brand name Mounjaro, was up to three times more effective than semaglutide, or Ozempic, at helping adults achieve weight loss. That conclusion comes from a study billed as the largest real-world data analysis of its kind, which monitored 18,386 patients on the medications over the course of a year.


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Researchers tracked the subjects' body weight at three months, six months and one year after starting either Mounjaro or Ozempic. At the three-month mark, they found that patients on Mounjaro had experienced an average -5.9% change in body weight compared to an average -3.6% change for those on Ozempic. At the six-month mark, Mounjaro users saw an average -10.1% change in weight while Ozempic users saw an average of -5.9%. And after a year, patients on Mounjaro experienced an average -15.2% change in body weight; their peers on Ozempic experienced an average -7.9% change.

Based on these results, the study's authors concluded that adults on Mounjaro were "significantly more likely to achieve clinically meaningful weight loss and larger reductions in body weight" than those on Ozempic.

Underlying conditions did impact the results, as patients without type 2 diabetes tended to experience larger reductions in body weight; while those with diabetes maxed out at a -7.5% change in weight at one year, those without reached up to -9%. About half of the subjects in the study had type 2 diabetes.

Certain demographics were overrepresented in the research. Over 70% of the study's subjects were women and even more — 77% — were white. The average age was 52, while the average weight at the start of the study was about 243 pounds. All subjects were considered overweight or obese on the body mass index.

As the study authors note, the research lines up with previously published trials demonstrating Mounjaro's effectiveness. A 2022 study published in the New England Journal of Medicine found that 85% of patients on tirzepatide experienced a weight reduction of 5% or more. (In the Truveta analysis, it was 81.8%.) A Nature study from the same year found that 77% of adults on semaglutide reached that threshold. In both cases, however, the drugs were compared against placebos. Head-to-head trials like the Truveta study have been limited, until now.


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