Mounjaro Outperforms Ozempic in Weight Loss

A recent study, published on July 8, 2024, in the journal JAMA Internal Medicine, reveals that the medication Mounjaro (tirzepatide), also known under the name Zepbound, is more effective at facilitating weight loss than Ozempic (semaglutide), marketed as Wegovy. The research, spearheaded by Dr. Nicholas Stucky, vice president of research at Truveta Inc., indicates that individuals who are overweight or obese achieve more significant and clinically meaningful weight loss with tirzepatide compared to semaglutide.

The study observed over 18,000 overweight and obese participants who were prescribed either drug to manage their type 2 diabetes from May 2022 to September 2023. Both Mounjaro and Ozempic were originally developed to treat type 2 diabetes but have since been approved for weight loss treatment.

Findings from the study show that while both medications are effective in aiding weight reduction, Mounjaro outperforms Ozempic. Approximately 82% of participants on Mounjaro lost at least 5% of their body weight, in contrast to nearly 67% of those on Ozempic. Furthermore, a significant portion of Mounjaro users experienced more substantial weight loss; 42% shed 15% or more of their body weight, whereas only 18% of Ozempic users achieved similar results.

Overall, patients on Mounjaro were observed to be 76% more likely to lose 5% or more of their body weight compared to those on Ozempic. They were also 2.5 times more likely to lose 10% or more and 3.2 times more likely to lose 15% or more of their body weight. Additionally, Mounjaro users experienced larger reductions in body weight throughout their first year on the medication.

The weight loss progression for Mounjaro users was notable at various intervals: after three months, they had lost about 6% of their body weight compared to less than 4% for Ozempic users; at six months, the figures were 10% versus 6%; and at one year, the difference widened to 15% versus 8%.

Both medications function by mimicking the gut hormone GLP-1, which is crucial in maintaining stable blood sugar levels and also aids in slowing digestion and increasing satiety. However, Mounjaro has an added effect as it stimulates another gut hormone called GIP, potentially explaining its enhanced effectiveness in weight loss.

The key takeaway from this study is that while both tirzepatide and semaglutide are effective in managing weight loss for overweight and obese individuals, Mounjaro provides a more substantial and significant reduction in body weight over time. This finding could influence future decisions in prescribing weight-loss medications for individuals struggling with obesity and type 2 diabetes.