Do GLP-1 Medications Like Ozempic Affect Sperm Count and Male Fertility?

 

Written by: Mate Health Clinical Education Team
Medically reviewed by: Nicholas Farber, MD
Published: July 2026

GLP-1 medications are widely used for obesity and type 2 diabetes. Semaglutide is the active ingredient in Ozempic and Wegovy. Tirzepatide, a dual GIP and GLP-1 receptor agonist, is sold as Mounjaro and Zepbound.

As more men take these medications, a practical question has followed: Can they affect sperm count, testosterone, or the ability to conceive?

The available evidence is encouraging for some men but still limited. Early human studies have not identified a consistent harmful effect on semen parameters. Some small trials in men with obesity, type 2 diabetes, or obesity-related low testosterone have reported improvements in testosterone and selected sperm measures.

GLP-1 medications are not fertility treatments, however, and researchers still need larger and longer studies before drawing firm conclusions on the impact of these medications on sperm health.

What You Need to Know

A peer-reviewed 2026 systematic review of 10 studies involving 639 men found that GLP-1 medications were associated with increased total testosterone, particularly in men with obesity, type 2 diabetes, or functional hypogonadism. Some studies also reported improvements in semen parameters, although the authors concluded that additional long-term controlled studies are still needed.[1]

A separate systematic review of five randomized trials presented as a conference abstract at the ENDO 2026 Annual Meeting reached a similar cautious conclusion: GLP-1 medications may improve reproductive hormones and semen parameters in obese hypogonadal men, mostly within the context of weight loss.[2]

Most studies have been small, lasted only a few months, and focused on men with obesity or type 2 diabetes. The findings cannot be generalized to all men, every GLP-1 medication, or long-term use.

Based on the evidence available today:

• GLP-1 medications have not been shown to consistently reduce sperm count or quality and likely are not beneficial in non-obese men
• Weight loss and improved metabolic health may drive the improvement in testosterone and some semen parameters in men with obesity.
• There is not enough evidence to definitively assess the role of GLP-1 medications in patients with male infertility

Why Body Weight and Metabolic Health Matter

Obesity can affect male reproductive health through several overlapping pathways. Excess body fat can increase the conversion of testosterone to estrogen, contribute to inflammation and insulin resistance, and disrupt the hormonal signals involved in sperm production.

Men with obesity are more likely to have lower testosterone, and in some studies was also linked to lower sperm concentration, total sperm count, motility, or morphology. These effects vary, and obesity does not always lead to infertility.

GLP-1 medications can improve blood sugar regulation and support weight loss by reducing appetite and slowing digestion. When testosterone or semen quality improves during treatment, the benefit may come mainly from improved metabolic health rather than a direct effect of the medication on the testes.

The evidence does not show that a metabolically healthy man should take a GLP-1 medication to improve fertility. It suggests that treating obesity and metabolic disease may reduce factors already working against reproductive health.

What the Human Studies Show

The S-LITE trial provides the most rigorous data on the subject [3]. In this randomized trial, 56 men with obesity (BMI 32–43) underwent an 8-week low-calorie diet (mean weight loss 16.5 kg), then were randomized to 52 weeks of a GLP-1 (liraglutide), exercise, combination, or placebo for weight maintenance. Diet-induced weight loss increased sperm concentration 1.49-fold and total sperm count 1.41-fold. These improvements were maintained at 52 weeks in men randomized to liraglutide (or exercise) who sustained weight loss, but not in those who regained weight. Liraglutide did not harm semen parameters and helped sustain the weight loss that drove the sperm benefit.

Another frequently cited study was a 24-week randomized, open-label trial in 25 men with obesity, type 2 diabetes, and functional hypogonadism, randomized to semaglutide or testosterone replacement. Baseline semen quality in the cohort was poor. Among men receiving semaglutide, median normal morphology rose from 2% to 4% and total testosterone increased. Testosterone therapy improved testosterone but reduced sperm concentration and count, an expected concern because external testosterone can suppress natural sperm production [4].

In contrast, a 4-week randomized trial of dulaglutide (a GLP-1) in 24 healthy normal weight men found no significant changes in any sperm parameters versus placebo over a 4 week timespan. This showed that a GLP-1 medication neither harmed nor helped sperm health in normal weight men [5].

Overall, the findings show favorable preliminary benefits on fertility in men with obesity, with the caveat that current studies are small and too inconsistent to definitively draw conclusions. Further, GLP-1 medications likely do not have any sperm health benefit in normal weight men.

What Happens to Testosterone?

The testosterone findings in GLP-1 patients are generally more consistent than the semen findings. Weight loss in men with obesity can increase testosterone, and several GLP-1 studies have reported higher total testosterone after treatment.

Testosterone replacement therapy (TRT), a common treatment for hypogonadal symptoms, has a negative side effect of suppressing the hormonal signals needed for sperm production. Men who start testosterone replacement therapy almost always have a reduction in their sperm count and motility.

GLP-1 medications work differently. When testosterone improves during GLP-1 treatment, it is generally thought to result from weight loss and improved metabolic function rather than the introduction of external testosterone. That may allow testosterone to improve without the same direct suppression of sperm production associated with testosterone replacement therapy.

What Researchers Still Do Not Know

There are still important gaps in the research:

Long-term effects: Many studies lasted only 16 to 24 weeks. That is not enough to establish reproductive safety over several years.

Differences between medications: Semaglutide, liraglutide, dulaglutide, and tirzepatide are not interchangeable. Male fertility data are stronger for some medications than others.

Effects in healthy-weight men: Most human data involve men with obesity, diabetes, low testosterone, or a combination of these conditions.

Pregnancy and live-birth outcomes: Better semen parameters do not necessarily translate into a higher chance of pregnancy or live birth.

DNA fragmentation: Human studies have not established whether GLP-1 medications meaningfully improve or worsen sperm DNA fragmentation

Rapid weight loss and nutrition: Significant calorie restriction, poor protein intake, or nutritional deficiencies could affect overall health and potentially reproductive function, regardless of which medication produces the weight loss.

Do Men Need to Stop a GLP-1 Before Trying to Conceive?

There is currently no established recommendation for men to stop semaglutide, tirzepatide, or other GLP-1 medications before attempting conception. Neither the FDA labels for these medications nor the reproductive and endocrine literature impose a discontinuation requirement on men [6,7]. Animal studies found no effect on sperm morphology, mating, fertility, or conception, although animal findings cannot fully predict human outcomes [7].

The commonly cited recommendation to stop semaglutide at least two months before a planned pregnancy applies to women who may become pregnant. It is based on the medication’s long half-life and concern about fetal exposure.

When Semen Testing May Be Useful

A semen analysis may be useful when:

• Fertility is a near-term goal.
• A couple has been trying to conceive without success.
• There is a history of low testosterone, diabetes, obesity, varicocele, testicular injury, surgery, chemotherapy, or another reproductive risk factor.
• A man wants a baseline before starting or changing a medication.
• A physician recommends monitoring after a meaningful change in weight, health, or treatment.

Sperm production takes about 90 days to complete, so changes in health, medication, or lifestyle may not be fully reflected immediately. Testing too soon after a change can largely reflect sperm that began developing before the change occurred.

Mate Health’s Comprehensive Semen Analysis reports 20 clinical parameters, including volume, concentration, total sperm count, rapidly progressive, slowly progressive, non-progressive and immotile sperm, morphology, velocity, and calculated functional sperm metrics.

Samples are analyzed in a CLIA-certified, CAP-accredited high-complexity andrology laboratory using WHO 6th Edition (2021) methodology. [8] A full list is available on the Mate Health What We Report page.

Mate Health’s Advanced Semen Analysis reports 22 parameters, including all 20 Comprehensive parameters plus DNA Fragmentation Index and vitality testing. Sperm microscopy images are also included for physician review.

Taking a GLP-1 medication does not automatically mean these tests are needed. They may still be useful as part of a broader fertility evaluation.

Practical Guidance

Tell the prescribing physician that conception is a goal. This allows medication decisions to account for both metabolic health and reproductive planning.

Consider a baseline semen analysis when fertility is a near-term concern. Objective results are more useful than trying to infer sperm health from medication use, body weight, symptoms, or testosterone alone.

Allow enough time before retesting. Because sperm production takes about 90 days to complete, a repeat test is generally more informative after a full development cycle unless a physician recommends otherwise.

Review abnormal results with a reproductive urologist or fertility specialist. A semen analysis is one part of the evaluation and should be interpreted alongside medical history, physical examination, hormone testing, and the female partner’s evaluation when applicable.

Frequently Asked Questions

Do Ozempic or Wegovy lower sperm count?

Current human studies have not shown a consistent reduction in sperm count from semaglutide. A small trial in men with obesity, type 2 diabetes, and low testosterone found improved morphology and increased testosterone, but larger studies are needed.

Should a man stop semaglutide two months before trying to conceive?

There is no established recommendation for male partners to stop semaglutide medication prior to conceiving. The commonly cited recommendation to stop semaglutide two months before trying to conceive applies to females who are planning a pregnancy.

Does Mounjaro or Zepbound affect male fertility?

Human fertility data specific to tirzepatide remain limited. Current evidence does not establish that it harms male fertility, but it has not been proven to improve fertility either.

Medical Disclaimer

This article is for educational purposes and is not medical advice. Research on GLP-1 medications and male fertility remains limited, and individual risks and benefits vary.

Speak with a physician, endocrinologist, reproductive urologist, or fertility specialist before changing medication or making treatment decisions.

References

1. Deameh MG, Ramez M, Rowaiee R, et al. Effects of glucagon-like peptide-1 receptor agonists on male reproductive hormones, semen parameters, and metabolic outcomes: a systematic review. J Sex Med. 2026;23(2):qdaf381. doi:10.1093/jsxmed/qdaf381.
2. Natesh P, Muhammad J, Abedi H. Effect of glucagon-like peptide-1 agonist on the hypothalamic-pituitary-gonadal axis in males. ENDO 2026 Annual Meeting; Abstract MON-157. Presented June 15, 2026. Conference abstract.
3. Andersen E, Juhl CR, Kjøller ET, et al. Sperm count is increased by diet-induced weight loss and maintained by exercise or GLP-1 analogue treatment: a randomized controlled trial. Hum Reprod. 2022;37(7):1414-1422. doi:10.1093/humrep/deac096.
4. Gregorič N, Šikonja J, Janež A, Jensterle M. Semaglutide improved sperm morphology in obese men with type 2 diabetes mellitus and functional hypogonadism. Diabetes Obes Metab. 2025;27(2):519-528. doi:10.1111/dom.16042.
5. Lengsfeld S, Probst L, Emara Y, et al. Effects of the glucagon-like peptide-1 receptor agonist dulaglutide on sexuality in healthy men: a randomised, double-blind, placebo-controlled crossover study. EBioMedicine. 2024;107:105284. doi:10.1016/j.ebiom.2024.105284.
6. U.S. Food and Drug Administration. Wegovy Prescribing Information.
7. U.S. Food and Drug Administration. Zepbound Prescribing Information.
8. World Health Organization. WHO Laboratory Manual for the Examination and Processing of Human Semen. Sixth Edition. 2021.