GLP-1 weight-loss drugs show no hormone suppression in men, review finds

A systematic review of five randomized controlled trials presented this week at the Endocrine Society’s annual meeting found that GLP-1 weight-loss medications do not suppress male reproductive hormones. The analysis examined data from men ages 18 to 65 taking the drugs and measured testosterone, related brain hormones, sex-hormone-binding globulin, semen quality, weight, cholesterol and blood sugar.

Study findings Results indicated that men with obesity-linked low testosterone may see gains in testosterone levels, sperm quality and metabolic markers during weight loss. One 16-week trial of liraglutide showed hormone improvement in obese men with functional hypogonadism.

Another liraglutide study reported higher sperm concentration and count. A 24-week semaglutide trial found better sperm shape and lower LDL cholesterol while total testosterone stayed the same. A four-week dulaglutide study showed no significant changes in reproductive hormones or sexual function.

Expert comment and limits "This provides early evidence that GLP-1 medications taken by obese men with hypogonadism/low testosterone improves testosterone levels," Dr. Anthony Puopolo said. "If this finding continues to gain evidence, GLP-1s might be a better option for low T than testosterone replacement therapy in obese men – as GLP-1 medications preserve fertility, whereas TRT tends to be harmful to male reproductive/sperm function," he added.

The review authors noted the small number of trials and called for larger studies focused on male reproductive outcomes.