Pratibha Natesh and her team in Coventry, UK, were sifting through clinical data when they uncovered a promising shift: men with obesity-related low testosterone on GLP-1 drugs weren’t just losing weight—they were seeing hormonal and reproductive benefits, too. At ENDO 2026 in Chicago, the endocrinology community listened closely as the team from University Hospitals Coventry and Warwickshire and Warwick Medical School presented findings that could reshape how doctors approach male fertility and hormonal health. For years, testosterone replacement therapy has been the go-to for men with low T, but it often comes with a hidden cost—suppressed sperm production. Now, GLP-1 medications like semaglutide and liraglutide are emerging as a different kind of solution, one that treats the root cause: metabolic dysfunction tied to obesity.
The team analyzed five randomized controlled trials involving men aged 18 to 65, focusing on changes in testosterone, sperm quality, and metabolic markers. What they found was reassuring—GLP-1s did not harm male hormones or fertility. In fact, the opposite appeared true. A 24-week trial with semaglutide showed improved sperm morphology and cholesterol levels, with stable testosterone. Even more striking, a 16-week liraglutide study revealed increases in both testosterone and luteinizing hormone in men with obesity-related hypogonadism—improvements that outpaced those seen with testosterone replacement alone. These drugs aren’t just managing weight or blood sugar; they’re restoring the body’s natural hormonal balance.
Dr. Natesh emphasizes that this isn’t a shortcut to fertility, but a paradigm shift. “This work 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 implications are profound: instead of replacing hormones, doctors may soon focus on enabling the body to produce them again. While the sample size of existing trials remains small and long-term data is still limited, the consistency of metabolic and reproductive improvements is hard to ignore.
Still, caution remains. GLP-1s are not approved to treat infertility or hypogonadism, and their reproductive benefits appear indirect—tied to weight loss and improved insulin sensitivity. Yet for patients and physicians alike, the message is clear: better metabolic health can unlock more than just a lower number on the scale. As larger, more targeted studies get underway, one truth is already emerging—when it comes to male fertility, what’s good for the heart may also be good for the future of fatherhood.