New research from the United Kingdom suggests that weight-loss drugs known as GLP-1 receptor agonists, including Ozempic, Mounjaro, Wegovy, and Saxenda, may improve fertility markers in obese men. The study, conducted by researchers at University Hospitals Coventry and Warwickshire and Warwick Medical School, indicates that these medications could positively influence testosterone levels and sperm quality by promoting weight loss.

Obesity is widely recognized as a factor that can impair male fertility. Excess body fat may contribute to lowering testosterone, disrupting hormonal balance, and increasing the risk of erectile dysfunction, all of which hinder reproductive health. The researchers emphasized that weight loss achieved through GLP-1 injections appears to restore these fertility-related parameters rather than the drugs having a direct hormonal effect.

The study pooled data from five clinical trials involving men aged 18 to 65, evaluating the impact of different GLP-1 treatments over periods ranging from four to six months. One trial involving Wegovy observed improved sperm morphology, while another examining Saxenda noted increases in testosterone and related sex hormones. Importantly, no adverse effects on hormone levels, sexual function, or sperm quality were reported during these trials.

Dr. Pratibha Natesh, the lead author of the study, described the findings as supporting a change in clinical practice. Rather than prescribing testosterone replacement therapy for men with obesity-related low testosterone, the focus should shift toward addressing the root cause—excess weight. Improving metabolic health, she noted, has broader benefits that extend beyond mere weight reduction, potentially preserving fertility and restoring natural hormone balance.

According to the researchers, infertility affects approximately one in seven couples in the UK, with factors such as age, stress, and weight playing significant roles for both men and women. The study’s results were presented at a recent Endocrine Society conference, where experts highlighted the potential of these treatments to help mitigate the reproductive consequences of obesity.

While the evidence points to the benefit of GLP-1 receptor agonists in improving fertility markers through weight loss, further research is needed to confirm long-term effects and fully understand the mechanisms involved. Nonetheless, this development marks a promising avenue for addressing male infertility linked to obesity by focusing on metabolic health rather than hormone replacement alone.