It’s a battle of the sexes.
The diabetes-turned-weight-loss drug Mounjaro has been making headlines for its effectiveness at helping people shed pounds, even delivering better results than Ozempic.
And when it comes to who loses more weight on the blockbuster drug, research has found one group comes out on top.
People of all ages have been using the once-weekly injections, especially younger generations with type 2 diabetes looking to lower their blood sugar levels.
Age is just a number, though, according to a study published in the journal Obesity that examined the effects of tirzepatide — the active ingredient in Mounjaro — in adults with overweight or obesity.
Among more than 1,000 patients, women lost significantly more weight than men after using the drug for more than a year.
Researchers measured the percentage of total body weight lost across three age groups, split by gender: adults under 45, those between 46 and 59 and those 60 and older.
After 15 months of continuous treatment, women had lost 15% of their body weight, compared with nearly 11% for men.
The researchers also examined other factors that could affect the amount of weight lost.
While participants under 45 did lose more weight than those over 60 — 15% in the younger group compared with 12% — age was not the strongest predictor of results.
In addition to being female, greater weight loss was also seen in people who didn’t have type 2 diabetes, had never used a weight-loss medication before and took a higher dose of tirzepatide.
Women have historically had a tougher time losing weight due to lower muscle mass, hormonal shifts and differences in how the body stores fat, among other reasons.
However, other studies have also found that women tend to lose more weight than men on GLP-1s, the class of medications that includes tirzepatide and Ozempic.
In a meta-analysis of nearly 20,000 people taking drugs such as semaglutide and dulaglutide, women lost about 11% of their body weight, compared with about 7% for their male counterparts.
Once again, the researchers compared factors that could influence weight loss, including age, race, ethnicity and body mass index, and found that gender was the factor associated with the largest difference.
There are a few theories as to why women appear to have vastly different results.
One centers on how women’s bodies clear the drug from the bloodstream more slowly than men’s.
Hormones may also enhance a GLP-1 effects, particularly estrogen, which helps regulate appetite, fullness, energy use and insulin sensitivity.
And the benefits of Mounjaro for women may extend beyond shrinking waistlines.
Other studies have also found that women taking GLP-1 drugs may be less likely to develop breast cancer.
