Overview
- Research presented this week at the Endocrine Society meeting in Chicago pooled five small randomized trials and found that GLP‑1 treatments were associated with higher or stable testosterone and improvements in some sperm measures after courses up to 24 weeks in men with obesity.
- Investigators say the reproductive gains tracked with weight loss and better metabolic markers, pointing to reduced inflammation and restored hypothalamic‑pituitary‑gonadal signaling rather than a direct testicular drug effect.
- Results across trials were mixed by drug and duration: short studies of dulaglutide showed no change while liraglutide and a 24‑week semaglutide trial reported hormone or sperm improvements.
- Clinicians caution that the evidence is limited to obese men, is short term and heterogeneous, and that rapid large weight loss can itself alter fertility, so men planning to conceive should seek fertility evaluation and medical guidance.
- Authors and experts say larger, longer randomized trials explicitly powered to measure male reproductive outcomes are needed before clinicians change practice or recommend GLP‑1s as a fertility treatment.