Tirzepatide is a once-weekly GIP/GLP-1 receptor agonist used for weight reduction in adults with obesity. A new analysis of the SURMOUNT clinical trials reveals that the medicine leads to significant weight reduction, with women experiencing greater reductions in weight compared to men. Obesity is a global health concern affecting millions of adults, and recent studies have shown that drugs targeting specific hormones involved in energy balance, such as GLP-1, can help people lose weight effectively and safely. Tirzepatide targets both GIP and GLP-1 receptors and has shown promising results for weight loss.
The SURMOUNT-1 trial looked at how well tirzepatide works for weight loss in people with obesity or overweight who do not have diabetes. A post-hoc analysis of the SURMOUNT program, which included four clinical trials, revealed that a weekly injection of tirzepatide results in substantial weight loss for both men and women, with women experiencing greater reductions in weight. The analysis compared tirzepatide to a placebo over 72 to 88 weeks in 4,677 adults with obesity. Logistic regression was used to evaluate whether male and female participants differed in achieving specific weight loss milestones.
Across the four trials, women made up the majority of participants and both men and women had similar BMI levels at the start of the trials. The estimated reduction in body weight for those taking tirzepatide was significantly greater than for those on placebo, regardless of sex. Women saw a greater percentage of weight loss than men across all doses, with women losing up to 24.6% of their body weight compared to 18.1% in men. Both men and women were far more likely to achieve reductions in body weight with tirzepatide compared to placebo.
In terms of safety outcomes, both men and women had similar results, though women reported higher rates of nausea and vomiting. The lead researcher cautioned that further research is needed to understand the potential mechanisms behind the greater weight loss in women compared to men. Medical experts not involved in the research noted that the findings are promising and could lead to more personalized treatment plans for weight loss. The study may help prescribing providers set more realistic expectations based on gender for patients seeking these medications, with the potential for changing dosing based on gender in the future.
