Fat jabs could boost testosterone and sperm quality

Weight loss injections may improve testosterone levels and sperm quality in obese men.

Blockbuster injections known as GLP-1 drugs could tackle one of the root causes of male infertility by addressing excess weight and poor metabolic health, scientists say.

Obesity is already linked to a number of serious conditions, including diabetes and cancer. But experts warn that it can also disrupt hormone levels, impair sperm production and damage the shape, movement and number of sperm, making it harder for couples to get pregnant.

Now a review by researchers from Coventry and Warwickshire University Hospitals and Warwick Medical School has found that the drugs may provide benefits far beyond weight loss.

The team analyzed five studies involving men ages 18 to 65 and found that GLP-1 treatments had no adverse effects on hormones, sexual function or sperm quality.

Instead, the results pointed to improvements.

A 24-week study found that semaglutide, the active ingredient in Wegovy and Ozempic, improved sperm shape and cholesterol levels while keeping hormone levels stable.

Another found that liraglutide, sold as Saxenda, increased testosterone levels within four months in men with low testosterone due to obesity. Their overall health outcomes were also better than those treated with testosterone replacement therapy (TRT) alone.

Dr Pratibha Natesh, from Warwick Medical School, said: “This study supports a shift from prescribing testosterone replacement therapy in men with obesity and low testosterone to treating the underlying cause, excess weight and poor metabolic health, which can naturally restore hormone levels and preserve fertility.”