GLP-1 drugs may boost male fertility markers

Clinical Takeaway: GLP-1 receptor agonists don’t appear to acutely suppress the male hypothalamic-pituitary-gonadal axis and may improve testosterone and some semen parameters in men with obesity-related low testosterone, but they shouldn’t yet be considered infertility or hypogonadism treatments.

As GLP-1 receptor agonists become increasingly common for obesity and type 2 diabetes, clinicians need clearer guidance on whether these therapies affect male hormones, semen quality, and fertility.

A systematic review of randomized controlled trials suggests GLP-1 receptor agonists may be reassuring for reproductive health in men — and potentially beneficial in those with obesity-related functional hypogonadism.

Researchers from University Hospitals Coventry and Warwickshire and Warwick Medical School searched PubMed and the Cochrane Library for RCTs of men aged 18 to 65 years who received a GLP-1 receptor agonist with an appropriate comparator. Five trials met inclusion criteria. Outcomes included total testosterone, LH, FSH, SHBG, semen parameters, BMI, weight, lipids, and HbA1c.

Two acute infusion studies of native GLP-1 in healthy men found no meaningful changes in mean LH, FSH, or total testosterone, though one study reported reduced testosterone pulse frequency without changes in LH. A 4-week dulaglutide crossover trial in healthy men found no significant changes in reproductive hormones, sexual function scores, or semen quality, while HbA1c improved.

Longer studies in men with obesity showed more encouraging reproductive signals. In a 16-week liraglutide trial of men with obesity and functional hypogonadism, total testosterone, LH, and FSH increased, with overall health outcomes superior to testosterone replacement therapy. A 24-week semaglutide trial found improved sperm morphology and LDL cholesterol while preserving testosterone and gonadotropins. A liraglutide weight-loss maintenance study reported improved sperm concentration and total sperm count.

“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,” said Pratibha Natesh, M.B.B.S., M.R.C.P., M.Res., of Warwick Medical School.

The research was presented at ENDO 2026, the Endocrine Society’s annual meeting, and hasn't yet been peer reviewed.

Source: Natesh P, et al. Endocrine Society Annual Meeting, Abstract MON-157. June 15, 2026. Effect of Glucagon Like Peptide-1 Agonist on Hypothalamo-Pituitary-Gonadal Axis in Males