Tirzepatide (Mounjaro) outperforms semaglutide (Ozempic) in real-world comparative effectiveness weight loss study

In a groundbreaking comparative effectiveness study using real-world data, Truveta Research has examined the weight loss potential of tirzepatide (Mounjaro) and semaglutide (Ozempic), showing that overweight or obese US adults were significantly more likely to achieve weight loss when taking tirzepatide. The research has been published as a preprint* in MedRxiv.

Conducted using Truveta Data, Truveta Research examined data from over 40,000 patients initiating either tirzepatide or semaglutide between May 2022 and September 2023. Semaglutide, a glucagon-like peptide 1 receptor agonist-based (GLP-1 RA) medication, and tirzepatide, a dual GLP-1 RA/gastric inhibitory polypeptide (GIP) medication, are used to treat patients with type 2 diabetes or obesity. The analysis of this unadjusted population revealed distinctive characteristics between patients taking the medications, with tirzepatide users generally being younger, better educated, having fewer co-morbidities, and lacking type 2 diabetes, despite both medications being predominantly taken by white females.

Through the implementation of rigorous methodologies, including the use of propensity score matching, Truveta Research then compared the effectiveness of semaglutide with tirzepatide for weight loss cohort of 18,000 patients. The subsequent analysis of these patients revealed that compared to semaglutide, patients taking tirzepatide were:

• 8 times more likely to achieve 5% weight loss
• 6 times more likely to achieve 10% weight loss
• 3 times more likely to achieve 15% weight loss

Tirzepatide users also experienced notable reductions in body weight at various intervals, outperforming semaglutide users:

• At 3 months, the mean percentage change in body weight was -5.9% for tirzepatide users, compared to -3.6% for those taking semaglutide.
• At 6 months: -10.1% vs -5.9%
• At 1 year: -15.2% vs -7.9%

Interestingly, the study highlighted that weight loss was more pronounced for patients without type 2 diabetes, although the disparity in effectiveness between tirzepatide and semaglutide remained consistent. Gastrointestinal adverse event rates were comparable between the two medications.

Nick Stucky, vice president of Truveta Research, and an author on the paper, emphasized the significance of the study: “GLP-1 medications have already changed the way physicians treat type 2 diabetes and obesity, but little real-world data exist to compare the effectiveness of the two most common medications, Ozempic and Mounjaro.” Underscoring the study’s significance in providing real-world insights into the comparative effectiveness of semaglutide and tirzepatide, Stucky highlighted that the availability of timely and comprehensive electronic health record (EHR) data allowed the researchers to advance their understanding of the head-to-head efficacy of these medications for weight loss, potentially influencing patient care and outcomes well ahead of randomised clinical trials.

Co-author, Tyler Gluckman, Providence Heart Institute, echoed the importance of assessing the real-world effects of these medications, particularly in light of the recent FDA approval of tirzepatide for type 2 diabetes, saying “As a practicing cardiologist and researcher, having the most timely data to inform patient care is paramount”. He emphasized that this research “has the power to greatly improve our understanding of how these agents are being used in every day practice and the effect that they’re having.”

*Editor’s note: The article published in MedRxiv is a preprint and has not been peer-reviewed. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.