GLP-1s improve male testosterone, sperm count, scientists say

A new survey examining the rising usage of GLP-1 drugs leads MedicalWatch for March 3, 2026.

Fertility may not be a reason for men to avoid GLP-1 medications. In fact, they could see an improvement.

After 24 weeks of treatment with GLP-1s, a class of medications that treats diabetes and is prescribed widely for weight loss, men ages 18 to 65 saw improved testosterone levels, sperm count, and size and shape of sperm, said principle investigator of the study Dr. Pratibha Natesh, a consultant endocrinologist at University Hospitals Coventry and Warwickshire and honorary clinical lecturer at Warwick Medical School in England.

About 15 per cent of couples in the United States have trouble conceiving, and more than half of those couples have a male infertility problem, according to Yale Medicine. Health-care providers define infertility as not conceiving after 12 months of regular, unprotected sexual intercourse.

More studies need to be done before GLP-1s are prescribed as a first-line treatment for male infertility, said Dr. Lidia Mínguez Alarcón, a Spanish reproductive epidemiologist and assistant professor of medicine at Brigham and Women’s Hospital and Harvard Medical School in Massachusetts. She was not involved in the research.

However, the results do suggest that men considering GLP-1s for weight loss or medical conditions may want to ponder possible benefits for their fertility as well, Natesh said.

Why a metabolic drug may improve fertility

Weight loss that often comes with taking GLP-1s can help with healthier hormone function, including testosterone levels, Natesh said. If further studies continue to show that GLP-1s are a good treatment for male infertility, the drugs could provide a better alternative to testosterone replacement therapy, which can suppress sperm production, she added.

Taking GLP-1 medications also may reduce inflammation and metabolic stress, which can limit sperm production, Natesh said.

The research was only conducted on men with high body mass index, so it is hard to say if the rest of the population would also see benefits to their fertility, Minguez Alarcón said.

It is also important to note that some people may have trouble losing weight because of hormone problems, not always that the hormone problems are a result of weight, said Dr. Amin Herati, a urologist and director of male infertility and men’s health at Johns Hopkins Hospital. He was not involved in the research.

To know “if it’s the chicken or the egg,” Herati stressed the importance of having a fertility evaluation with a reproductive urologist.

And not all weight loss is helpful to fertility, Herati added.

A sudden change in the amount of body fat, as seen from bariatric surgery and sometimes from GLP-1 medications, may signal to the brain that it is not a safe time to reproduce and limit fertility, he added. He recommends working with a doctor for guidance on healthy behaviours.

What else men can do to improve fertility

When is it time to ask about your fertility? If you are looking to conceive, it could be after 12 months of unsuccessful attempts. And for everyone, important signs include symptoms like a decrease in libido, low energy, change in body composition and difficulty maintaining erections.

But improving reproductive health isn’t just for those looking to become a parent, Minguez Alarcon said.

Good semen quality and healthy levels of testosterone have been associated with better long-term health in men, she said.

In addition to working with medical professionals, people can improve their fertility and health through restricting ultraprocessed foods, getting regular exercise, limiting sedentary habits, reducing toxic chemical exposures and avoiding wet heat such as hot showers or hot tubs multiple times a day, Herati said.

Getting good sleep and reducing smoking and alcohol consumption are important as well, Natesh said.

And men who do want to conceive a child should keep their health-care providers informed, as that may influence treatment options, she said.

Madeline Holcombe, CNN