AS GLP-1 AGONISTS soar in popularity—about 12 percent of the U.S. population has tried one, most often Ozempic or Wegovy (semaglutide)—researchers are scrambling to understand their potential side effects, including the sexual ones like erectile dysfunction (ED).
Guys on GLP-1 agonists keep bringing up getting it up and other sexual side effects—especially on Reddit. When researchers in Italy analyzed thousands of Reddit threads about GLP-1 agonists, the drug class that includes Ozempic and Wegovy, (Victoza and Saxenda (liraglutide), Trulicity (dulaglutide), Mounjaro and Zepbound (tirzepatide), they found a wide range of comments about sex. Users reported everything from “less drive” to a libido “through the roof.”
If you’re on these, don’t panic. “There may be marked differences in age, sex, severity of underlying disease, and duration of therapy (e.g. whether newly started or on maintenance),” says study author Davide Arillotta, MD, a psychiatrist at the University of Florence. Individual hormonal and lifestyle factors might play a role in how you respond to these drugs, too, said Dr. Arillotta.
The research on GLP-1s and ED is young and the takeaways are likely nuanced. Here’s what to know about it so far.
How GLP-1s are linked with ED
IN A RECENT study in the International Journal of Impotence Research, scientists were surprised to find that men ages 18 to 50 who took semaglutide for weight loss, but not diabetes, were more likely to develop erectile dysfunction and low testosterone levels than men who didn’t use the meds.
“We know that weight loss generally has a positive effect on testosterone levels and sexual function, and as it turned out, the data showed the exact opposite,” says study author Joseph Sonstein, MD, assistant professor of surgery in the Division of Urology at the University of Texas Medical Branch.
The study can’t prove cause and effect—more research is needed. “We're not proposing that semaglutide causes erectile dysfunction or that it causes low testosterone, but there's an association between the two,” says Dr. Sonstein.
So, what’s going on here? It could be a case of mixed signals. GLP-1 agonists help guys shed fat by imitating the actions of GLP-1, a hormone we produce to help regulate blood sugar and weight. Since these drugs work by mimicking hormones, “perhaps there is some sort of cross reactivity with some of the signaling that has to do with testosterone production,” says Dr. Sonstein.
Fortunately, the overall risk of developing ED or low T in the study was small—less than 2 percent—even in the men who took semaglutide.
“By no means would I, based on this study, counsel men to avoid these medications if they're indicated for other medical reasons,” says Dr. Sonstein.
Other small studies on different GLP-1 agonists turned up different results. In a study in eBioMedicine, dulaglutide (Trulicity) did not affect testosterone or sperm count in healthy guys with normal T levels. In a study in the Journal of Clinical Medicine, a certain group of men actually improved their erectile function and sperm count over four months—but the men were specifically those with obesity and metabolic hypogonadism (a type of low T closely linked with diabetes) who used liraglutide. They also had higher T at the end of treatment than men who didn’t use liraglutide. The theory about the results here is that weight loss might affect brain cells involved in a particular hormonal signaling system (the hypothalamic-pituitary-testicular axis) that is impaired in men with metabolic hypogonadism, the researchers say.
As with any medication, discuss the risks and benefits of GLP-1 agonists with your doctor. In obesity, the benefits, like a reduced risk of heart attacks and strokes, may outweigh the small risk of sexual side effects, says Dr. Sonstein.
If you notice your erections are weaker than usual, tell the doctor who prescribed the drugs. Tell your primary care physician, too. “Any patient who has a new onset of erectile dysfunction or symptoms of low testosterone should be evaluated,” says Dr. Sonstein.
Unlike ED, which is obvious, low T can be tricky. The symptoms, like low energy and fatigue, often overlap with other problems, Dr. Sonstein says.“One of the more specific symptoms of low T is decreased libido, so when sex drive is really the issue, to me, that kind of perks my ears up a little bit to say this person might have low T,” he said.
Your doctor can check your T with a simple blood test. They might also refer you to a urologist for further workup.