New research indicates that GLP-1 receptor agonists, widely used for weight management, could also play a role in addressing male infertility, particularly in men struggling with obesity. Scientists from University Hospitals Coventry and Warwickshire and Warwick Medical School reported that these drugs led to notable increases in testosterone, sperm count, and improvements in sperm size and shape.
Dr. Pratibha Natesh of Warwick Medical School emphasized that the findings support a broader shift in treatment philosophy. “The analysis supports a shift away from prescribing testosterone replacement in men with obesity and low testosterone and toward treating the underlying cause — excess weight and poor metabolic health — which can naturally restore hormone levels and preserve fertility,” she said.
The study, which tracked men aged 18 to 65 over 24 weeks, found that liraglutide boosted levels of testosterone, luteinizing hormone, and follicle-stimulating hormone. Semaglutide, meanwhile, was associated with improved sperm morphology. “Improving metabolic health can have positive effects far beyond weight alone,” Natesh added.
Obesity has long been linked to low testosterone and poor sperm health. Excess body fat can reduce testosterone production and lower sex hormone-binding globulin (SHBG), a protein that helps transport testosterone in the bloodstream. This creates a cycle where low testosterone makes weight loss harder, further impairing fertility.
The broader context of fertility challenges is stark. According to Yale Medicine, about 15% of couples in the United States struggle to conceive, and male infertility is a contributing factor in more than half of those cases. This aligns with broader demographic trends; a recent report highlighted that the iPhone era has been linked to a U.S. fertility plunge, with births hitting a record low in 2025.
While GLP-1 drugs are not a cure-all, the study suggests they could be a valuable tool for men whose fertility issues stem from metabolic dysfunction. This approach contrasts with traditional hormone replacement therapy, which can sometimes further suppress natural sperm production.
Healthcare experts caution that more research is needed to determine long-term effects and optimal treatment protocols. However, the potential to restore fertility by addressing root causes like obesity marks a significant shift in reproductive medicine.
