Ozempic and other GLP-1 medications have become some of the most widely used weight-loss drugs in the world. They promise dramatic fat loss, better blood sugar control, and improved long-term health.

As more men start using these medications researchers are uncovering a side of the story that has not been widely discussed. There are unexpected sexual side effects.

A major new study from the University of Texas Medical Branch (UTMB) is the first to signal a surprising link between semaglutide (the active ingredient in Ozempic and Wegovy) and men’s sexual health. According to the findings, men taking semaglutide showed a 4.5× higher risk of erectile dysfunction and nearly double the risk of testosterone deficiency compared to similar men not taking the drug.

These risks are small in absolute numbers, most men will not experience them, but the relative increase is significant enough to raise concern and prompt deeper investigation.

Let’s break down what this means, why it matters, and what men should know before starting Ozempic.

What the Study Found: The Numbers Every Man Should Know

The research team reviewed data from thousands of non-diabetic, obese men aged 18 to 50. All had similar health profiles, and none had a prior diagnosis of erectile dysfunction or low testosterone.

After comparing men who were prescribed semaglutide with those who were not the researchers found:

1. Erectile Dysfunction Risk Increased ~4.5×

Men taking semaglutide were far more likely to receive a new diagnosis of erectile dysfunction or a prescription for ED medications such as PDE-5 inhibitors. In the treated group 1.47% had ED or a PDE-5 prescription compared with 0.32% in the matched control group.

2. Testosterone Deficiency Risk Nearly Doubled

The rate of newly diagnosed testosterone deficiency was 1.53% in men prescribed semaglutide compared with 0.80% in the control group.

3. Absolute Risks Were Small but the Pattern Was Clear

While only around 1–1.5% of men developed these issues among semaglutide users the increase compared with the control group was large enough to be statistically meaningful.

This is the first major peer-reviewed study showing such a link. It challenges many assumptions about how weight-loss drugs affect male hormones and sexual function.

Why These Results Are Surprising

Traditionally weight loss improves men’s sexual health. Losing fat often boosts testosterone levels, improves blood flow and restores more balanced hormone function.

In fact other reviews of GLP-1 medications have suggested that GLP-1 therapy could lead to improved testosterone and sexual function for some men.

That is why the new association observed by UTMB researchers is unexpected. Instead of seeing hormone levels rise and sexual function improve, a small but notable group of men developed lowered testosterone and new erectile issues.

This suggests that semaglutide may have unique effects on the hormonal or nervous system pathways that govern sexual function especially in certain individuals.

What Could Be Causing These Sexual Side Effects

The study cannot prove causation but researchers and experts have proposed several possible explanations:

Rapid Weight Loss and Hormone Shifts

Rapid changes in fat mass and energy balance may transiently disrupt testosterone production or hormone regulation. The body may respond differently during abrupt weight loss than during gradual lifestyle-driven weight change. This could temporarily lower testosterone or affect sexual function.

Direct Effects on Hormonal Regulation

GLP-1 receptors may influence more than just appetite and metabolic control. Some scientists speculate that GLP-1 agonists might affect brain areas or endocrine pathways that regulate reproductive hormones, which could influence libido or erectile capacity.

Vascular or Autonomic Effects

GLP-1 drugs can influence vascular tone and autonomic (nerve) function, which are important for erection. For a subset of men these effects, combined with rapid weight loss, might impair blood flow or nerve signaling needed for normal erectile function.

Increased Monitoring and Detection Bias

Because weight-loss drugs often spur greater medical follow-up, people on semaglutide may see doctors more often. That could increase the detection of issues such as ED or testosterone deficiency compared to men not under similar scrutiny.

Should Men Be Worried? Here Is the Real Answer

Not necessarily, but they should be informed.

The study shows that the relative risk increases are real, but the absolute number of men affected is still small. Most men taking Ozempic will not develop serious sexual side effects.

However because weight-loss medications like semaglutide are becoming very common, even small risks can affect many people. For any man, sexual health changes are deeply personal and can impact confidence, relationships, and quality of life.

Signs Men Should Watch For

After starting semaglutide, men (or their partners) might observe:

• Lower sex drive
• Difficulty achieving or maintaining erections
• Reduced morning erections
• Reduced libido or sexual desire
• Fatigue, mood changes, or other changes in energy or motivation
• Reduced muscle strength or mood swings

If symptoms appear and persist after weeks or months on semaglutide it might be worth discussing with a clinician.

What to Do If You Notice Sexual Side Effects

Talk to Your Healthcare Provider

Do not stop medication on your own without medical guidance. If symptoms develop a doctor can evaluate potential causes such as hormone levels (testosterone, thyroid, etc.), vascular health, mental health, or other medications.

Consider Monitoring Hormones

If you begin semaglutide, you may ask your clinician about baseline and follow-up hormone testing (testosterone, free testosterone, LH/FSH, etc.), especially if you notice any sexual symptoms.

Look at Lifestyle Factors

Resistance training, good nutrition, sufficient sleep, and stress management may help support healthy hormone levels, especially during weight loss.

Balance Benefits vs Risks

For many patients the metabolic and weight-loss benefits of semaglutide may outweigh possible risks. But you should make an informed decision with your doctor, understanding both benefits and potential downsides.

Why This Study Is Not the Final Word

The UTMB study is important because it offers the first large real-world data linking semaglutide with increased risk of ED and low testosterone. But it has limitations: its observational design cannot prove causation. There may be unmeasured confounding factors such as lifestyle, other medications, psychological stress, or health-seeking behavior differences between the groups.

Because the absolute rates are low, and other studies suggest possible beneficial effects of GLP-1 drugs on hormones for some men, the overall picture remains mixed. Researchers call for prospective trials specifically designed to measure sexual function and hormone levels before and after semaglutide therapy.

The Bottom Line

The UTMB research uncovered a signal that weight-loss treatment with semaglutide may carry underreported risks for men’s sexual health, including erectile dysfunction and testosterone deficiency. While these risks appear in only a small percentage of users, the increased relative risk merits attention and awareness.

If you are considering or already using Ozempic for weight loss talk to your doctor. Be aware of possible sexual side effects, monitor how you feel, and weigh the metabolic benefits against potential changes in sexual health and hormone balance.

References:

- Able C, Liao B, Saffati G, et al. Prescribing semaglutide for weight loss in non-diabetic obese patients is associated with an increased risk of erectile dysfunction: a TriNetX database study. *International Journal of Impotence Research*, 2025. https://pubmed.ncbi.nlm.nih.gov/38778151/

- University of Texas Medical Branch. UTMB Study Finds Increased ED Risk in Some Semaglutide Users. UTMB News (March 26, 2025). https://www.utmb.edu/news/article/utmb-news/2025/03/26/wait---ozempic-is-linked-to-ed

- Endocrine Society. GLP-1 Therapy and Male Hormones: Mixed Evidence at ENDO 2025 Press Release. Endocrine.org. https://www.endocrine.org/news-and-advocacy/news-room/endo-annual-meeting/endo-2025-press-releases/portillo-canales-press-release

- News-Medical. Increased risk of erectile dysfunction with semaglutide in non-diabetic obese patients. News-Medical.net (May 26, 2025). https://www.news-medical.net/news/20240526/Increased-risk-of-erectile-dysfunction-with-semaglutide-in-non-diabetic-obese-patients.aspx

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