Weight loss medications that belong to the GLP-1 class may improve male fertility, according to findings presented at the Endocrine Society’s annual meeting. These drugs, commonly used for managing obesity and diabetes, appear to have a positive impact on reproductive hormones and sperm quality in men, particularly those struggling with obesity-related hypogonadism.
Obesity is a known factor contributing to male fertility issues. Excess weight can disrupt the hypothalamic-pituitary-gonadal (HPG) axis, a hormone system crucial for regulating testosterone production. This disruption can lead to functional hypogonadism, characterized by abnormally low testosterone levels and impaired semen quality.
The research involved a systematic review of five randomized controlled trials analyzing data from men aged 18 to 65 who were taking GLP-1 medications. The studies measured various parameters, including testosterone levels, related brain hormones, sex hormone-binding proteins, semen quality, weight, BMI, cholesterol, and blood sugar.
Results indicated that GLP-1 medications do not suppress male reproductive hormones. Instead, men with obesity and low testosterone linked to their weight may experience improvements in testosterone levels, sperm quality, and overall metabolic health, especially as they lose weight.
One four-week study involving dulaglutide showed no significant changes in reproductive hormones or sexual function. However, a separate 16-week trial of liraglutide demonstrated improvements in hormone levels for obese men with functional hypogonadism. This review suggested liraglutide might offer better health outcomes compared to hormone replacement therapy in these cases. Another study with liraglutide reported enhanced sperm concentration and count.
A 24-week trial of semaglutide, marketed as Ozempic and Wegovy, observed improvements in sperm morphology and reductions in unhealthy cholesterol levels, while maintaining total testosterone.
The study authors concluded that GLP-1s "do not appear to acutely suppress the male HPG axis and may improve reproductive hormones and semen parameters in obese hypogonadal men, largely within the context of weight loss." They also emphasized that the evidence base is limited, with only five trials included, and called for larger randomized controlled trials specifically designed to assess male reproductive outcomes.
Experts noted the significance of these early findings. Dr. Anthony Puopolo, a men's health expert, commented that this provides preliminary evidence that GLP-1 medications can improve testosterone levels in obese men with hypogonadism. He expressed optimism that if further research supports these results, GLP-1s could become a preferable option over testosterone replacement therapy for obese men, as TRT can negatively impact male reproductive and sperm function, while GLP-1s appear to preserve fertility.