Weight-Loss Drugs Show Surprising Benefit for Men

Clear Facts

• Research presented at ENDO 2026 shows GLP-1 weight-loss medications may improve male fertility and testosterone levels in obese men
• Studies found that drugs like Ozempic and Wegovy preserve testosterone while improving sperm quality, unlike traditional testosterone replacement therapy
• The findings are based on five randomized controlled trials, with researchers calling for larger studies to confirm the reproductive benefits

Men struggling with obesity-related fertility issues may have found an unexpected ally in popular weight-loss medications, according to research presented this week at the Endocrine Society’s annual meeting in Chicago.

The study examined how GLP-1 drugs — the class of medications that includes Ozempic and Wegovy — impact reproductive hormones and metabolic health in men. The findings suggest these medications could offer a superior alternative to traditional testosterone replacement therapy for obese men dealing with low testosterone.

Excess weight contributes to serious disruptions in the hypothalamic-pituitary-gonadal (HPG) axis, the hormone system responsible for testosterone production. This can lead to functional hypogonadism, a condition where testosterone levels drop abnormally low due to disrupted hormone signaling. These changes also impair semen quality, making it harder for men to father children.

Researchers conducted a systematic review of five randomized controlled trials involving men aged 18 to 65 taking GLP-1 medications. The studies measured testosterone levels, brain hormones involved in testosterone and sperm production, and proteins that carry sex hormones in the blood. Scientists also tracked semen quality, weight, BMI, cholesterol, and blood sugar levels.

The results challenged concerns that these weight-loss drugs might suppress male hormones. Instead, men with obesity and low testosterone linked to excess weight experienced improved testosterone levels, better sperm quality, and enhanced metabolic health — especially as they lost weight.

In one four-week study examining dulaglutide, researchers found no significant changes in reproductive hormones or sexual function.

A separate 16-week trial using liraglutide showed improved hormone levels in obese men with functional hypogonadism, where low testosterone was directly related to obesity. The review determined that liraglutide delivered better health outcomes than traditional hormone replacement therapy.

Another liraglutide study reported improvements in sperm concentration and count.

A 24-week trial of semaglutide — sold commercially as Ozempic and Wegovy — demonstrated improvement in sperm shape and reduced bad cholesterol while preserving total testosterone levels.

The researchers acknowledged that with only five trials included, the evidence base remains limited. More research is necessary to establish a stronger association between GLP-1 drugs and male fertility improvements.

In their research abstract, the 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.”

“However, evidence remains limited and heterogeneous, underscoring the need for larger RCTs explicitly powered to assess male reproductive outcomes,” they wrote.

Dr. Anthony Puopolo, men’s health expert and lead medical provider for RexMD, weighed in on the findings.

“This provides early evidence that GLP-1 medications taken by obese men with hypogonadism/low testosterone (low T) improves testosterone levels,” he said.

While acknowledging that more research is necessary, Puopolo, who was not involved in the study, expressed optimism about how GLP-1s could transform treatment for male fertility issues.

“If this finding continues to gain evidence, GLP-1s might be a better option for low T than testosterone replacement therapy (TRT) in obese men – as GLP-1 medications preserve fertility, whereas TRT tends to be harmful to male reproductive/sperm function,” he added.

The potential advantages of GLP-1 medications over traditional testosterone therapy are significant. While testosterone replacement therapy can suppress natural sperm production and harm fertility, these weight-loss drugs appear to preserve reproductive function while addressing the underlying metabolic issues contributing to low testosterone.

For American men dealing with obesity-related health challenges, these findings represent a potential breakthrough in addressing multiple health concerns simultaneously — weight loss, improved metabolic markers, and preserved or enhanced fertility.

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