GLP-1 anti-obesity medications are linked with improvements in testosterone levels and health outcomes for men with obesity or type 2 diabetes, researchers reported in San Francisco at ENDO 2025, opens new tab, the Endocrine Society’s annual meeting.
Weight loss from lifestyle changes or bariatric surgery is known to boost testosterone levels, but the impact of anti-obesity medications has not been widely investigated, study leader Dr. Shellsea Portillo Canales of SSM Health St. Louis University Hospital in Missouri said in a statement.
Portillo Canales and colleagues tracked 110 men with obesity – many also with type 2 diabetes – who were being treated with semaglutide, dulaglutide or tirzepatide, the active ingredients in Novo Nordisk’s Wegovy and Ozempic or Eli Lilly’s Trulicity, Mounjaro, and Zepbound.
The average age was 54. None of the men were receiving other testosterone-boosting medications.
During 18 months of treatment, the proportion of men with testosterone levels in the normal range rose from 53% to 77%.
Testosterone plays a critical role in male sexual functioning but can also impact bone mass, fat distribution, muscle mass, strength and red blood cell production.
In the current study, the greater the weight loss, the greater the improvement in testosterone levels, the researchers found.
While the study cannot prove GLP-1 drugs caused low testosterone levels to normalize, it does show a direct correlation, Portillo Canales noted.
INTERMITTENT ACCESS TO GLP-1 DRUGS STILL YIELDS WEIGHT LOSS
Popular GLP-1 anti-obesity medications are effective for weight loss even when treatment is inconsistent, new findings suggest.
Patients often face challenges in accessing these medications – such as Novo Nordisk’s Wegovy and Ozempic and Eli Lilly’s Zepbound and Mounjaro – due to supply shortages and insurance coverage obstacles, study leader Kaelen Medeiros of privately held weight-loss company Calibrate in New York said in a statement.
Medeiros and colleagues looked at how interruptions to GLP-1 medication access over the course of two years impacted weight-loss outcomes in 6,392 clients of Calibrate’s online metabolic health program. Along with the drugs, the program also included intensive lifestyle interventions and coaching on diet, exercise, sleep and emotional health.
Overall, 72.5% of participants experienced at least one disruption in their GLP-1 treatment and 11.1% had multiple disruptions, Medeiros reported at ENDO 2025.
Participants who faced access issues reported a 13.7% weight loss within 12 months and a 14.9% loss within 24 months, on average. Those without treatment interruptions reported a 17% weight loss in 12 months and 20.1% in 24 months, on average.
Even those who received no more than four treatments over 12 months also achieved clinically significant weight loss, with more than 10% change in body weight on average.
“While unpredictable GLP-1 medication access is frustrating, the good news is that our research shows effective weight loss can still be achieved if paired with appropriate lifestyle changes and coaching support,” Medeiros said.
