AMIDST THE TALK, the promise, and the endless celebrity stories about weight loss drugs like Ozempic, there are still a few questions that don’t get as much play. One of them is whether these new drugs raise or lower your testosterone levels.

About one in eight Americans have taken a glucagon-like peptide-1 (GLP-1) agonist medication, like Ozempic or Wegovy, according to the Kaiser Family Foundation.

In case you’re not sure exactly how they work, GLP-1 agonists mimic the GLP-1 hormone receptor, which is created in the small intestine and regulates the way food passes through the stomach. The drugs boost the brain’s energy-burning capabilities and reduce energy-storing, helping you lose weight.

The injectable medications are commonly used to treat type 2 diabetes, but they’re also prescribed to help people lose weight. The Food and Drug Administration has approved some GLP-1 medications to treat obesity, including semaglutide (Wegovy and Ozempic) and liraglutide (Victoza and Saxenda).

Experts aren’t exactly sure how all of this affects your testosterone levels, says Paul Gittens, M.D., a urologist and founder of Rockwell Centers for Sexual Medicine & Wellness in Pennsylvania and New York City. However, taking GLP-1s has been shown to help people lose weight, and weight loss can help men who are overweight improve their testosterone.

“We’re still finding out new information that is positive, and there are going to be some negatives, as these medications roll out,” explains Dr. Gittens, who prescribes semaglutide to some of his patients.

But here’s what doctors do know about GLP-1s and testosterone.

Do GLP-1s raise or lower testosterone?

“I don’t think we know enough about the GLP-1 interaction at the testicle level to fully understand why it lowers or raises T levels,” says Chris Deibert, M.D., program director and associate professor of urologic surgery at the University of Nebraska Medical Center.

A small 2024 study published in Endocrine Abstracts showed that semaglutide was more effective than testosterone replacement therapy in improving body composition and increasing testosterone for men with type 2 diabetes.

Another study suggested that the GLP-1 liraglutide improved sex hormone levels and semen quality in obese male mice. The medication also helped them lose weight and improve reproductive functioning.

On the flip side, research published in the Journal of Sexual Medicine in 2024 showed that men without diabetes who were prescribed semaglutide had a higher rate of developing erectile dysfunction and low testosterone. But the overall rates were still low. Less than 4 percent received a diagnosis of testosterone deficiency, and 1.4 percent had ED.

More research is needed on GLP-1s and testosterone to fully understand the effects, says Michael Wierschem, M.D., a urologist and founder of Dallas Men’s Health. But he says that so, far the risk of low testosterone and erectile dysfunction is low—and it shouldn’t stop guys from asking about or taking the medications, as weight loss offers many other health benefits.

Plus, many medications bring side effects for some people, Dr. Gittens says. He suggests clinicians get a base testosterone level for men taking GLP-1s and discuss their potential effects on T levels.

“This is something that should be on our radar,” he adds.

Why weight loss is important for testosterone?

Obesity is one factor that can lower testosterone, and losing weight can typically improve your levels, Dr. Wierschem says.

Taking GLP-1s is one way to help you lose weight, but he says that there are limits. Weight loss while on the drugs can vary, from about 5 to 30 pounds on average, according to the Mayo Clinic, and some people lose more. Lifestyle changes, like exercise and diet adjustments, are recommended, too.

“In my clinic, we make sure when we put somebody on semaglutide, we also put them on a diet and exercise plan,” Dr. Wierschem says. “It’s important to combine all of that. You can’t just take semaglutide and expect to lose 100 pounds.”

Weight loss also improves sexual function overall, Dr. Gittens adds. When someone loses weight, they usually have more energy and feel better in general. It also lowers their risk for diabetes, cardiovascular disease, and other health conditions.

“Weight loss is important for men with or without low testosterone,” Dr. Deibert notes.

What happens to testosterone when you stop taking GLP-1?

Suppose you’re taking GLP-1s and have lost weight and seen your T levels improve. Doctors aren’t sure what might happen if you suddenly stop taking the weight-loss drugs, Dr. Wierschem says.

“There’s not good scientific evidence to say one way or the other,” he says. “But if they stop the semaglutide, and they start gaining weight, their bioavailable testosterone will certainly go down.”

But if you’re continuing to lose weight, build muscle, and lose fat, your testosterone should remain in a healthy range, Dr. Gittens says.

While GLP-1s can be taken long term, he says some men might not want to take them forever. So working with a doctor to develop lifestyle habits that help you come off the medications effectively may be important.

Can you take semaglutide with testosterone therapy?

Even if they’re on a weight-loss journey, many men still take testosterone replacement therapy (TRT)—and there are no issues with taking both TRT and semaglutide, Dr. Gittens says.

You can also take medications for erectile dysfunction while taking GLP-1s, he said.

TRT can also help increase energy levels, which can subsequently help with weight loss, which also improves testosterone, Dr. Wierschem says. “Everything goes hand in hand, and they work together.”

While on TRT, you’ll need to get your T levels checked every few months to ensure that it’s working, he adds. You also don’t always have to take testosterone forever.

Should you try taking GLP-1 to improve testosterone?

Weight loss medications aren’t a panacea, Dr. Deibert says. “Raising energy by normalizing testosterone or losing weight with semaglutide will help a guy feel better so that he can get into an exercise routine to help him achieve his ultimate goals.”

It’s a “jumpstart,” Dr. Gittens adds. “We always want to make sure we’re looking at lifestyle,” and working with your doctor on a plan can help.

For the best results for your weight, testosterone levels and sexual health, you’ll need to exercise regularly, including lifting weights, and eat a healthy diet, too, he emphasizes. Reducing stress and getting plenty of sleep can also affect your testosterone.

“It’s important to know that taking testosterone is fine, taking semaglutide is fine, but these other measures are equally as important,” Dr. Wierschem says.