GLP-1 weight-loss drugs may not harm male fertility and could improve it, ENDO 2026 review finds
A new systematic review presented at the Endocrine Society's ENDO 2026 meeting suggests GLP-1 weight-loss drugs do not harm male fertility and may even improve it in men with obesity. Across five clinical trials reviewed by UK researchers, two showed higher testosterone and bette
Millions of men take GLP-1 weight-loss drugs such as semaglutide, and a new systematic review suggests those drugs may not harm fertility and could even improve it. Scientists at Warwick Medical School and University Hospitals Coventry and Warwickshire in the UK pooled five randomized controlled trials presented at the Endocrine Society's ENDO 2026 annual meeting. Across the trials, GLP-1 medications did not damage male hormones, sexual function, or sperm quality with long-term use. Two of the five trials showed active benefits: a 24-week semaglutide study found improved sperm shape and better cholesterol with stable hormone levels, while a 16-week liraglutide study found rising testosterone in men with obesity and low testosterone. Researchers believe the gains are driven mainly by weight loss, which can rebalance hormones and reduce inflammation that harms sperm production. Every man studied had a high body mass index, so the findings do not yet apply to men of normal weight, and researchers say larger trials are needed before GLP-1 drugs could be used to treat infertility.