Sildenafil and Fertility: Does Viagra Affect Sperm?

Sildenafil and Fertility: What You Need to Know

Published: 17 October 2026

Sildenafil and fertility are not negatively linked—current evidence suggests that sildenafil (Viagra) does not harm sperm quality or reduce male fertility, and may even help couples conceive by improving erectile function when trying for a baby [1][9]. Sildenafil is a PDE5 inhibitor used to treat erectile dysfunction (ED) by increasing blood flow to the penis during sexual stimulation. Many men worry that taking medication for ED might affect their ability to father children, but research has not shown sildenafil to cause fertility problems in men.

Does Sildenafil Affect Male Fertility?

Sildenafil does not appear to reduce male fertility or damage sperm. Studies examining sildenafil's effect on sperm parameters—including sperm count, motility (movement), and morphology (shape)—have found no harmful impact [9]. The medication works by inhibiting an enzyme called phosphodiesterase type 5 (PDE5), which helps relax blood vessels in the penis to allow an erection when sexually aroused. This mechanism does not interfere with the production or quality of sperm in the testes.

In fact, some research has explored whether sildenafil might improve certain aspects of sperm function, particularly motility, though results have been mixed and this is not an approved use of the drug. For men experiencing erectile dysfunction while trying to conceive, sildenafil can be a helpful tool to achieve successful intercourse at the right time in the menstrual cycle, thereby supporting conception efforts rather than hindering them [1][2].

If you have concerns about fertility, it is important to discuss them with your GP or a fertility specialist. Erectile dysfunction itself can sometimes be linked to underlying health conditions—such as diabetes, cardiovascular disease, or hormonal imbalances—that may also affect fertility, so addressing ED can be part of a broader approach to reproductive health [10].

How Sildenafil Works and Why It Doesn't Harm Sperm

Sildenafil works by blocking the PDE5 enzyme, which breaks down a substance called cyclic GMP. By preventing this breakdown, sildenafil allows blood vessels in the penis to stay relaxed and dilated, improving blood flow and making it easier to achieve and maintain an erection when sexually stimulated [3]. This action is localised to the blood vessels and does not affect the hormonal pathways or cellular processes involved in sperm production (spermatogenesis), which occurs in the testes.

Sperm are produced continuously in the seminiferous tubules of the testes under the control of hormones such as testosterone, follicle-stimulating hormone (FSH), and luteinising hormone (LH). Sildenafil does not interfere with these hormones or the maturation of sperm. Clinical trials and post-marketing surveillance have not identified any adverse effects on male reproductive function or offspring health when sildenafil is used as prescribed [9][12].

Because sildenafil is taken on demand—usually about one hour before sexual activity—and is cleared from the body relatively quickly (with a half-life of around 3–5 hours), it does not accumulate in tissues or exert long-term effects on the reproductive system. Men can use sildenafil safely while trying to conceive, provided it is appropriate for their overall health and any other medications they are taking.

Sildenafil and Sperm Quality: What the Research Says

Several studies have investigated whether sildenafil affects sperm parameters. The majority of evidence suggests no negative impact on sperm count, concentration, motility, or morphology in men taking sildenafil for erectile dysfunction [9]. Some laboratory studies have even suggested that sildenafil might enhance sperm motility in vitro, though this has not been conclusively proven to improve fertility outcomes in clinical practice and is not a licensed indication for the drug.

It is worth noting that erectile dysfunction and infertility can share common underlying causes, such as obesity, smoking, excessive alcohol consumption, poorly controlled diabetes, or cardiovascular disease [10]. Addressing these lifestyle and health factors can benefit both erectile function and fertility. If you are experiencing ED and have been trying to conceive without success for over a year (or six months if your partner is over 35), it is advisable to see your GP for a full assessment, which may include semen analysis and other fertility investigations.

Using Sildenafil When Trying to Conceive

If you are trying for a baby and experiencing erectile difficulties, sildenafil can help by making it easier to achieve an erection at the optimal time for conception. Timing intercourse around ovulation is important for maximising the chances of pregnancy, and ED can make this challenging. By improving erectile function, sildenafil supports couples in having regular, successful intercourse during the fertile window [1][2].

Sildenafil is taken on demand, typically about one hour before sexual activity, and works only when you are sexually aroused. The usual starting dose is 50 mg, which can be adjusted to 25 mg or 100 mg depending on effectiveness and side effects [3]. It is important to take sildenafil as directed and not to exceed one dose in 24 hours. The medication does not affect your partner's fertility or the developing embryo, as it is not passed on in semen in amounts that would have any biological effect.

Before starting sildenafil, you will need a consultation with a healthcare professional to ensure it is safe for you, particularly if you have heart conditions, take other medications, or have other health concerns. At Cured Pharmacy, our UK-registered prescribers review your medical history and current medications during an online consultation to ensure sildenafil is appropriate and safe for you.

Sildenafil and Fertility: Safety for Your Partner and Baby

A common question is whether sildenafil could affect a partner's fertility or harm a developing baby. The answer is no—sildenafil is not present in semen in clinically significant amounts, and there is no evidence that it affects female fertility, embryo development, or pregnancy outcomes [12]. The medication is metabolised and excreted by your body, and only trace amounts, if any, would be transferred during intercourse.

Sildenafil is not licensed for use in women for fertility purposes, and it should not be taken by pregnant or breastfeeding women unless specifically prescribed for a rare condition (such as pulmonary arterial hypertension) under specialist supervision. For men, however, using sildenafil while trying to conceive is considered safe and does not pose risks to your partner or future child [1][9].

If your partner is undergoing fertility treatment such as in vitro fertilisation (IVF) or intrauterine insemination (IUI), you can still use sildenafil if needed to provide a semen sample or for timed intercourse. Always inform your fertility clinic about any medications you are taking, so they have a complete picture of your health, but sildenafil use is unlikely to be a concern.

What If I'm Taking Other Fertility Medications?

Most fertility medications and supplements taken by men—such as folic acid, vitamin D, coenzyme Q10, or zinc—do not interact with sildenafil. However, it is essential to declare all medications and supplements during your consultation, as some drugs can interact with sildenafil and affect its safety or effectiveness [3][12].

For example, if you are taking medications for high blood pressure, heart conditions, or an enlarged prostate (alpha-blockers), these may interact with sildenafil and require dose adjustments or additional monitoring. Never take sildenafil if you use nitrate medications (such as GTN spray or isosorbide mononitrate) or recreational drugs known as 'poppers', as the combination can cause a dangerous drop in blood pressure [3]. Your prescriber will check for these interactions during your consultation to ensure sildenafil is safe for you.

Other ED Treatments and Fertility Considerations

Sildenafil is one of several PDE5 inhibitors available to treat erectile dysfunction. Other options include tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra). Like sildenafil, these medications work by improving blood flow to the penis and have not been shown to harm male fertility or sperm quality [4][5][6]. Tadalafil, for example, can last up to 36 hours, which may offer more flexibility for couples trying to conceive without the need to time medication as precisely.

The choice between different PDE5 inhibitors often comes down to personal preference, how quickly you want the medication to work, how long you want the effect to last, and any side effects you experience. All PDE5 inhibitors require sexual stimulation to work and are taken on demand (or, in the case of low-dose daily tadalafil, taken every day to allow spontaneity). None of these medications affect sperm production or fertility [2][8].

If PDE5 inhibitors are not suitable or effective for you, other treatments for ED include alprostadil (a cream or injection applied directly to the penis), vacuum erection devices, or psychological therapies such as cognitive behavioural therapy (CBT) if anxiety or stress is contributing to ED [1][7]. Your GP or a specialist can help you explore these options. Addressing underlying causes—such as improving cardiovascular health, losing weight, stopping smoking, or managing diabetes—can also improve both erectile function and fertility.

When to Seek Further Advice on Sildenafil and Fertility

If you have been trying to conceive for more than a year without success (or six months if your partner is over 35), it is important to see your GP for a fertility assessment. This may include a semen analysis to check sperm count, motility, and morphology, as well as investigations for your partner [1][2]. Erectile dysfunction can sometimes be an early sign of underlying health problems—such as cardiovascular disease, diabetes, or hormonal imbalances—that may also affect fertility, so it is worth getting a full health check [10].

Your GP can also review any medications you are taking, including sildenafil, and discuss whether any adjustments are needed. If you have concerns about how ED or its treatment might be affecting your ability to conceive, a fertility specialist or urologist can provide further advice and support. In some cases, referral to a specialist fertility clinic may be appropriate, particularly if there are other factors affecting conception.

At Cured Pharmacy, our online consultation process allows you to discuss your health, including any fertility concerns, with a UK-registered prescriber. While we can provide ED treatment, we always encourage you to see your GP for new or worsening ED, as it can be an important indicator of your overall health. Sildenafil and other PDE5 inhibitors are prescription-only medicines, and our prescribers will ensure they are safe and suitable for you based on your medical history and current medications.

Lifestyle Factors That Support Both Erectile Function and Fertility

Improving your general health can benefit both erectile function and fertility. Maintaining a healthy weight, eating a balanced diet rich in fruits, vegetables, whole grains, and lean protein, and taking regular physical activity can all support cardiovascular health and hormone balance [1][10]. Smoking is particularly harmful to both erections and sperm quality, so stopping smoking is one of the most effective steps you can take.

Limiting alcohol intake, managing stress, and getting enough sleep are also important. Excessive alcohol can worsen ED and reduce testosterone levels, while chronic stress can affect both sexual function and sperm production. If you have a long-term condition such as diabetes or high blood pressure, keeping it well controlled will help protect your erectile function and overall fertility. Your GP or practice nurse can support you with lifestyle changes and managing any underlying health conditions.

Scientific References

1. NHS. (n.d.). Erectile dysfunction (impotence). NHS website. https://www.nhs.uk/conditions/erection-problems-erectile-dysfunction/ [accessed 17 October 2026]
2. National Institute for Health and Care Excellence. (n.d.). Erectile dysfunction. Clinical Knowledge Summaries. https://cks.nice.org.uk/topics/erectile-dysfunction/ [accessed 17 October 2026]
3. Joint Formulary Committee. (n.d.). Sildenafil. British National Formulary. NICE. https://bnf.nice.org.uk/drugs/sildenafil/ [accessed 17 October 2026]
4. Goldstein, I., Lue, T. F., Padma-Nathan, H., Rosen, R. C., Steers, W. D., & Wicker, P. A. (1998). Oral sildenafil in the treatment of erectile dysfunction. New England Journal of Medicine, 338(20), 1397–1404. https://pubmed.ncbi.nlm.nih.gov/9580646/ [accessed 17 October 2026]
5. Feldman, H. A., Goldstein, I., Hatzichristou, D. G., Krane, R. J., & McKinlay, J. B. (1994). Impotence and its medical and psychosocial correlates: Results of the Massachusetts Male Aging Study. Journal of Urology, 151(1), 54–61. https://pubmed.ncbi.nlm.nih.gov/8254833/ [accessed 17 October 2026]
6. Electronic Medicines Compendium. (n.d.). Summaries of Product Characteristics and Patient Information Leaflets. https://www.medicines.org.uk/emc/ [accessed 17 October 2026]

Information on this page is for educational purposes only and is not medical advice. Prescription treatments require clinical assessment by a UK-registered prescriber. Always consult a qualified healthcare professional before starting or changing any medication.

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