Anti-obesity drugs may boost testosterone levels, study finds

Medications that target glucagon-like peptide-1 (GLP-1) could significantly improve testosterone levels and overall health outcomes in men and women living with obesity or type 2 diabetes, according to new research presented at the Endocrine Society’s 2025 annual meeting.

The study underlines the crucial role testosterone plays in maintaining bone mass, fat distribution, muscle mass, physical strength and red blood cell production.

“While it is well known that weight loss through lifestyle changes or bariatric surgery can raise testosterone levels, the effect of anti-obesity medications on these levels has not been extensively studied,” said Dr Shellsea Portillo Canales, an endocrinology fellow at SSM Health St Louis University Hospital. “Our study is among the first to provide compelling evidence that low testosterone can be reversed with the use of commonly prescribed anti-obesity medications.”

Maintaining adequate testosterone levels is key to preserving muscle mass and improving calorie burn during physical activity. Men living with obesity typically have testosterone levels that are 30 per cent lower than those of individuals with a healthy weight. Moreover, over 70 per cent of men with morbid obesity experience testosterone deficiency due to abnormally low hormone levels.

To investigate the relationship between testosterone and weight management, researchers analysed electronic health records from 110 men living with obesity and type 2 diabetes. The participants, who had an average age of 54, were undergoing treatment with semaglutide, dulaglutide or tirzepatide. None were taking testosterone replacement or hormonal therapies.

Testosterone levels, both total and free, were measured at baseline and throughout an 18-month period. The study found that participants experienced a weight reduction of 10 per cent, which was accompanied by a testosterone increase ranging from 53 per cent to 77 per cent.

“Results from this study show that there is a direct correlation between the use of anti-obesity medications and testosterone levels,” said Dr Portillo Canales. “Doctors and their patients can now consider this class of medications not only for managing obesity and controlling blood sugar, but also for supporting men’s reproductive health.”