Researchers have found that tirzepatide (Zepbound) is more effective than semaglutide (Wegovy) for weight loss, according to a study published in The New England Journal of Medicine. The double-blind trial, called SURMOUNT-5, involved 751 people with obesity but no type 2 diabetes, and showed that tirzepatide led to greater weight loss and reduction in waist circumference over 72 weeks.
Dr. Louis Aronne, a principal investigator and director of the Comprehensive Weight Control Center at Weill Cornell Medicine, highlighted that the results are consistent with previous findings but provide direct comparison. He noted that the greater efficacy of tirzepatide may be due to its dual mechanism of action involving both GLP-1 and GIP hormones, which help reduce hunger, lower blood sugar levels, and affect fat cell metabolism.
However, the study had limitations, including its open-label design with participants knowing their medication, which may introduce bias. Additionally, the study was funded by Eli Lilly, the manufacturer of Zepbound, raising potential conflicts of interest. Dr. Ada Londono, an obesity and internal medicine physician, emphasized the importance of medical history review and consultation with healthcare providers regarding potential side effects.
Dr. Rekha Kumar, a medical officer at the Found weight care program, stressed that while medication can aid weight loss, whole-person support is crucial for long-term success. The researchers are continuing to explore newer drugs like retatrutide, which mimics additional hormones such as glucagon, to enhance weight management outcomes.
Novo Nordisk, the company behind Wegovy, has acknowledged the study’s findings and emphasized that weight management involves more than just weight reduction, highlighting the need for a comprehensive approach to obesity treatment.