Does tadalafil affect sperm quality? This is a common concern for men taking this medication for erectile dysfunction who are planning to start a family. Tadalafil, a phosphodiesterase type 5 (PDE5) inhibitor available in the UK under brand names such as Cialis, works by enhancing blood flow to the penis. Current scientific evidence indicates that tadalafil does not adversely affect sperm parameters such as concentration, motility, or morphology. This article examines the research on tadalafil and male reproductive health, safety considerations, and when to seek medical advice about fertility concerns.

What Is Tadalafil and How Does It Work?

Tadalafil is a prescription medication primarily used to treat erectile dysfunction (ED) and the urinary symptoms of benign prostatic hyperplasia (BPH). It belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors, which also includes sildenafil and vardenafil. In the UK, tadalafil is available under brand names such as Cialis, as well as generic formulations approved by the Medicines and Healthcare products Regulatory Agency (MHRA).

The mechanism of action centres on the enzyme phosphodiesterase type 5, which is found in the smooth muscle cells lining blood vessels in the penis and other tissues. During sexual stimulation, nitric oxide is released in the penile tissue, which activates an enzyme that produces cyclic guanosine monophosphate (cGMP). This chemical messenger relaxes smooth muscle and dilates blood vessels, allowing increased blood flow to the penis and facilitating an erection. PDE5 normally breaks down cGMP, limiting the duration of this effect. By inhibiting PDE5, tadalafil allows cGMP to accumulate, thereby enhancing and prolonging the erectile response.

It's important to note that sexual stimulation is required for tadalafil to work effectively. Tadalafil is notable for its long duration of action—up to 36 hours—which distinguishes it from shorter-acting PDE5 inhibitors. It is available in different doses: lower daily doses (2.5 mg or 5 mg) for continuous use, and higher on-demand doses (10 mg or 20 mg) taken before anticipated sexual activity. The medication is absorbed relatively quickly, with peak plasma concentrations reached within two hours, and can be taken with or without food. Understanding how tadalafil works is important context when considering its potential effects on other aspects of male reproductive health, including sperm quality.

Research Evidence on Tadalafil and Male Reproductive Health

A common concern among men taking tadalafil is whether the medication might adversely affect sperm quality or fertility. Current scientific evidence suggests that tadalafil does not have a detrimental effect on sperm parameters and may, in some contexts, offer potential benefits to male reproductive health, though evidence for benefits is limited and heterogeneous.

Several clinical studies have investigated the impact of PDE5 inhibitors on semen quality. Research published in peer-reviewed journals has examined sperm concentration, motility (movement), morphology (shape), and DNA integrity in men taking tadalafil. The majority of these studies have found no significant negative effects on these parameters. Some small studies suggest tadalafil might improve certain aspects of sperm function, particularly sperm motility, though these findings are not consistent across all research.

The presence of PDE5 enzymes in sperm cells themselves may explain potential effects, as cGMP plays a role in regulating sperm movement and function. However, it is important to emphasise that tadalafil is not licensed to treat male infertility and is not recommended by NICE guidelines as a treatment to improve semen parameters.

It is important to note that whilst there is no established link between tadalafil use and reduced fertility, individual responses can vary. The underlying causes of erectile dysfunction—such as cardiovascular disease, diabetes, obesity, or psychological stress—may themselves be associated with reduced sperm quality. Therefore, any concerns about fertility should be assessed holistically, considering overall health status rather than attributing changes solely to medication use. Men who have pre-existing fertility issues or who are actively trying to conceive should discuss their medication regimen with their GP or a fertility specialist.

Safety Considerations When Taking Tadalafil

Tadalafil is generally well-tolerated, but like all medications, it carries potential side effects and contraindications that users should be aware of. Understanding these safety considerations is essential for anyone taking or considering this medication, particularly in the context of reproductive health planning.

Common adverse effects include:

• Headache

• Flushing (redness of the face and neck)

• Indigestion or dyspepsia

• Nasal congestion

• Back pain and muscle aches

• Dizziness

These effects are usually mild to moderate and often diminish with continued use. However, more serious adverse events, whilst rare, require immediate medical attention. These include sudden vision or hearing loss, chest pain during sexual activity, and priapism (a prolonged, painful erection lasting more than four hours), which constitutes a medical emergency.

Important contraindications and cautions include:

• Tadalafil must not be taken with nitrate medications (used for angina) or recreational drugs containing nitrites ('poppers'). Nitrates must not be used within at least 48 hours after taking tadalafil, as this combination can cause a dangerous drop in blood pressure

• Tadalafil must not be taken with guanylate cyclase stimulators such as riociguat

• If chest pain occurs while taking tadalafil, do not take nitrates and seek urgent medical attention (call 999 or attend A&E)

• Caution is advised in men with severe cardiovascular disease, recent stroke or heart attack, uncontrolled hypertension, or severe liver or kidney impairment

• Alpha-blockers (used for BPH or hypertension) may interact with tadalafil; patients should be on stable alpha-blocker therapy before starting tadalafil, with dose separation and blood pressure monitoring advised

• Certain medications can affect tadalafil metabolism, particularly CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, ritonavir) and inducers (e.g., rifampicin); grapefruit juice may increase tadalafil exposure

• Alcohol should be consumed in moderation due to the risk of additive hypotension and dizziness

From a reproductive health perspective, tadalafil does not affect hormone levels, including testosterone, and does not interfere with the hypothalamic-pituitary-gonadal axis that regulates sperm production. There is no evidence that paternal use of tadalafil increases the risk of birth defects, though human data are limited. There are no specific recommendations to discontinue tadalafil when attempting to conceive. However, as with any medication during conception planning, it is prudent to discuss ongoing treatment with your healthcare provider to ensure it aligns with your overall health goals.

If you experience any suspected side effects from tadalafil, report them via the MHRA Yellow Card scheme.

When to Speak to Your GP About Fertility Concerns

If you are taking tadalafil and have concerns about fertility or sperm quality, there are specific circumstances when you should seek medical advice. Open communication with your GP is essential for addressing these concerns appropriately and accessing further investigation or specialist referral if needed.

You should contact your GP if:

• You and your partner have been trying to conceive for 12 months or more without success (or six months if the female partner is 36 years or over)

• You have a history of testicular problems, including undescended testicles, testicular injury, or previous testicular surgery

• You have been diagnosed with conditions that may affect fertility, such as varicocele, hormonal disorders, or genetic conditions

• You are experiencing symptoms that might indicate reproductive health issues, such as testicular pain, swelling, or changes in sexual function beyond erectile difficulties

• You have concerns about how your current medications, including tadalafil, might be affecting your fertility

Seek urgent medical attention if you experience:

• Acute, severe unilateral testicular pain or swelling (possible testicular torsion) – attend A&E immediately

• A new painless testicular lump (possible testicular cancer) – request an urgent GP appointment (2-week-wait referral)

Your GP can arrange initial fertility investigations, which typically include a semen analysis—the primary test for assessing male fertility. This test evaluates sperm count, motility, morphology, and volume. According to NICE guidelines (Fertility problems: assessment and treatment, CG156), semen analysis should be offered early in the fertility assessment process. For accurate results, you should abstain from ejaculation for 2-7 days before the test. If abnormalities are detected, the test is usually repeated after at least three months, as sperm parameters can fluctuate.

Depending on the findings, your GP may also check hormone levels (testosterone, follicle-stimulating hormone, luteinising hormone) and screen for underlying conditions such as diabetes or thyroid disorders. If significant abnormalities are identified, such as azoospermia (no sperm), severe oligozoospermia (very low sperm count), or endocrine abnormalities, or if fertility issues persist, referral to a specialist fertility clinic or urologist with expertise in male reproductive health may be appropriate.

It is worth emphasising that erectile dysfunction and fertility are distinct issues. Many men with ED have normal sperm quality and can father children successfully. Conversely, some men with normal erectile function may have fertility problems. Taking tadalafil to address erectile difficulties does not preclude fertility, and there is no evidence to suggest that discontinuing the medication would improve sperm quality in men with normal semen parameters. A comprehensive, individualised approach to both sexual and reproductive health will ensure the best outcomes.

Frequently Asked Questions