The weight-loss drug Zepbound (tirzepatide) appears to be more effective in women than in men, according to a new analysis of clinical trial data presented at the European Association for the Study of Diabetes annual meeting in Madrid. The study, funded by Eli Lilly, the maker of Zepbound, pooled data from four trials involving nearly 3,000 women and 1,700 men. These trials included obese individuals, some with type 2 diabetes or other weight-related health issues, and some incorporated a three-month lifestyle intervention.
Differential Weight Loss by Sex
Across all trials and doses of tirzepatide, both women and men experienced significant weight loss. However, women achieved a more substantial reduction in body weight, losing up to 25% of their initial weight compared to 19% in men. This difference highlights a potential sex-based variation in response to the drug. Women lost 12% to 28% more weight on tirzepatide than placebo, while men lost 9% to 19% compared to placebo.
Dr. Luis-Emilio García, an associate vice president at Eli Lilly and lead researcher, noted, "This post-hoc analysis underscores the consistent benefits of tirzepatide for women and men. More research is needed to understand the mechanism by which females may experience more weight reduction in these trials."
Mechanism of Action
Tirzepatide functions by mimicking two hormones, GLP-1 and GIP, which are involved in regulating hunger and insulin. In contrast, Wegovy, a competing drug, only mimics GLP-1.
Trial Details and Safety Profile
The trials included participants with and without type 2 diabetes, assessing the drug's efficacy in diverse populations. The odds of reaching weight-reduction targets were significantly higher with tirzepatide compared to placebo across all trials. While the safety profile was generally similar between sexes, women reported a higher incidence of nausea and vomiting.
Expert Perspectives
Mir B. Ali, MD, medical director of MemorialCare Surgical Weight Loss Center, commented, "These findings may help prescribing providers set more realistic expectations based on gender for patients seeking these medications. It would be helpful to see more research in this area and make a consideration for changing dosing based on gender."
