Semaglutide improved sperm morphology in obese men with type 2 diabetes mellitus and functional hypogonadism.

Aims: To compare the effects of semaglutide and testosterone replacement therapy (TRT) on semen quality and parameters of functional hypogonadism (FH) in men with type 2 diabetes mellitus and obesity.

Materials and methods: We designed a randomised open-label trial in 25 men with type 2 diabetes (aged 50 [46-60] years, BMI 35.9 [32.8-38.7] kg/m²) and FH randomised to semaglutide (SEMA) 1 mg/week or intramuscular testosterone undecanoate (TRT) 1000 mg/10-12 weeks for 24 weeks. Semen analysis and parameters of FH were measured at baseline and after 24 weeks of treatment. Participants completed questionnaires of the International Index of Erectile Function-15 (IIEF-15) and the Aging Symptoms in Men (AMS).

Results: The quality of baseline sperm parameters of our study cohort was poor, below the 5th percentile of reference values. In the SEMA group, there was a significant increase in morphologically normal sperm from baseline to the end of the study (2% [2; 3.5] vs. 4% [2; 5.5]; p = 0.012), whereas sperm concentration and total number decreased significantly in the TRT group. Compared to TRT, the SEMA group had a significantly higher number of morphologically normal sperm, sperm concentration and total number. Both groups experienced an increase in total testosterone and improvement in the AMS score, whereas the IIEF-15 score significantly improved only in the TRT group.

Conclusion: Semaglutide markedly improved sperm morphology, total testosterone levels and symptoms of hypogonadism. These findings highlight semaglutide's potential as a therapeutic approach for men with obesity-related FH who desire fertility.

Clinical trial registration number: NCT06489457, www.

Clinicaltrials: gov.