Women have demonstrated a greater capacity for weight loss when using GLP-1 drugs, such as Mounjaro and Ozempic, according to a study published in the journal Obesity. The research examined the effectiveness of tirzepatide, the active ingredient in Mounjaro, in adults diagnosed with overweight or obesity.
Over a 15-month treatment period involving more than 1,000 participants, women lost an average of 15% of their total body weight. In comparison, men lost approximately 11% of their body weight during the same timeframe. These findings suggest that sex plays a more significant role in the drug's weight loss efficacy than age.
The study divided participants into three age groups: under 45, 46 to 59, and 60 and older. While younger participants (under 45) tended to lose more weight than older participants (over 60), with 15% weight loss in the younger group versus 12% in the older group, age was not identified as the strongest predictor of results.
Additional factors associated with greater weight loss included not having type 2 diabetes, never having used a weight-loss medication previously, and taking a higher dosage of tirzepatide.
Historically, women have faced greater challenges in losing weight due to factors such as lower muscle mass, hormonal fluctuations, and differences in fat storage. However, previous studies have also indicated a trend of women experiencing more significant weight loss on GLP-1 medications.
A meta-analysis of nearly 20,000 individuals taking drugs like semaglutide and dulaglutide found that women lost about 11% of their body weight, while men lost around 7%. This analysis also concluded that gender was the factor associated with the largest difference in weight loss outcomes.
Several theories attempt to explain why women appear to achieve different results. One hypothesis suggests that women's bodies may metabolize these drugs more slowly than men's. Hormones, particularly estrogen, which influences appetite regulation, energy use, and insulin sensitivity, may also enhance the effects of GLP-1 drugs. Furthermore, some research indicates that women taking GLP-1 drugs might have a reduced risk of developing breast cancer.