Dapoxetine is a selective serotonin reuptake inhibitor (SSRI) licensed in the UK specifically for premature ejaculation, not erectile dysfunction. Whilst both conditions affect sexual function, they involve entirely different mechanisms and require distinct treatments. Erectile dysfunction concerns difficulty achieving or maintaining an erection, whereas premature ejaculation relates to ejaculation timing. Understanding this distinction is essential for appropriate treatment. This article explains how dapoxetine works, why it does not treat erectile dysfunction, and what evidence-based options are available for men experiencing erectile difficulties in the UK.

What Is Dapoxetine and How Does It Work?

Dapoxetine is a selective serotonin reuptake inhibitor (SSRI) licensed in the UK specifically for the treatment of premature ejaculation (PE) in adult men aged 18–64 years. It is available as a prescription-only medicine under the brand name Priligy. Unlike other SSRIs used for depression or anxiety, dapoxetine has a rapid onset and short half-life, making it suitable for on-demand use rather than daily administration.

The recommended starting dose is 30 mg taken 1–3 hours before anticipated sexual activity. If the 30 mg dose is insufficient and well tolerated, your doctor may increase the dose to 60 mg. Dapoxetine must not be taken more than once in any 24-hour period. Your prescriber will review the benefit and tolerability of treatment after approximately four weeks or at least six doses to decide whether to continue.

The mechanism of action involves increasing serotonin levels in the synaptic cleft of neurons in the central nervous system. Serotonin plays a crucial role in modulating the ejaculatory reflex. By inhibiting the reuptake of serotonin, dapoxetine enhances serotonergic neurotransmission, which delays the ejaculatory response and improves control over ejaculation. This pharmacological effect specifically targets the neurological pathways involved in ejaculation timing.

It is important to understand that dapoxetine is not indicated for erectile dysfunction (ED). Erectile dysfunction involves difficulty achieving or maintaining an erection sufficient for satisfactory sexual performance, whereas premature ejaculation concerns the timing of ejaculation. These are distinct sexual health conditions with different underlying mechanisms. Dapoxetine has no direct effect on the vascular or neurological processes that govern erectile function, such as blood flow to the penis or the relaxation of smooth muscle tissue.

Important safety information: Dapoxetine can cause dizziness, light-headedness, and fainting (syncope), particularly when standing up quickly. Your prescriber will assess your risk of orthostatic hypotension before starting treatment. You should avoid alcohol whilst taking dapoxetine, as this increases the risk of these side effects. Do not drive or operate machinery until you know how dapoxetine affects you. Common side effects include nausea, dizziness, headache, and diarrhoea.

Dapoxetine must not be used if you:

• Are taking or have recently taken monoamine oxidase inhibitors (MAOIs), thioridazine, other SSRIs, SNRIs, or other medicines that increase serotonin levels (due to risk of serotonin syndrome)

• Are taking potent CYP3A4 inhibitors (such as ketoconazole, itraconazole, ritonavir, saquinavir, telithromycin, nefazodone)

• Have moderate to severe liver impairment

• Have severe kidney impairment

• Have certain heart conditions (heart failure, significant heart valve disease, or conduction abnormalities)

Dapoxetine is not recommended for men over 65 years of age. If you are taking medicines for erectile dysfunction (PDE5 inhibitors), combining them with dapoxetine may increase the risk of dizziness and low blood pressure; such combinations require medical supervision.

If you experience any side effects, including those not listed in the patient information leaflet, you should report them via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or through the Yellow Card app.

Differences Between Dapoxetine and ED Treatments

The fundamental difference between dapoxetine and erectile dysfunction treatments lies in their mechanisms of action and therapeutic targets. Medications for erectile dysfunction, such as sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra), and avanafil, belong to a class called phosphodiesterase type 5 (PDE5) inhibitors. These drugs work by enhancing blood flow to the penis through relaxation of smooth muscle and dilation of blood vessels, thereby facilitating the achievement and maintenance of an erection in response to sexual stimulation.

Dapoxetine, conversely, acts on the central nervous system to modulate serotonin levels and delay ejaculation. It does not influence penile blood flow, vascular function, or the physiological processes required for erection. Dapoxetine is not indicated for erectile dysfunction, and taking it will not improve erectile function in men with ED, as its pharmacological action does not target the mechanisms underlying erectile rigidity.

The conditions themselves also differ significantly in presentation and impact. Erectile dysfunction is characterised by consistent difficulty obtaining or sustaining an erection, which may stem from vascular disease, diabetes, neurological conditions, hormonal imbalances, or psychological factors. Premature ejaculation involves ejaculation that occurs sooner than desired, often within one minute of penetration, causing distress or interpersonal difficulty.

Treatment selection must be based on accurate diagnosis. Men experiencing sexual difficulties should consult their GP or a sexual health specialist for proper assessment. Using dapoxetine to address erectile problems would be inappropriate and ineffective. PDE5 inhibitors are not licensed for premature ejaculation and are not routinely effective for PE alone, though some evidence suggests they may help when erectile dysfunction coexists with PE; such decisions should be clinician-led. Some men may experience both conditions simultaneously, which requires a different therapeutic approach that addresses each concern separately with appropriate, evidence-based treatments.

When Premature Ejaculation and ED Occur Together

It is not uncommon for premature ejaculation and erectile dysfunction to coexist in the same individual, and understanding this relationship is important for effective management. Research suggests that some men with premature ejaculation may develop secondary erectile difficulties due to anxiety about ejaculating too quickly. This performance anxiety can interfere with arousal and erectile function, creating a cycle where both conditions reinforce each other.

Conversely, men with primary erectile dysfunction may experience what appears to be premature ejaculation because they rush to ejaculate before losing their erection. In these cases, the underlying problem is erectile dysfunction, and the apparent premature ejaculation is a compensatory response rather than a separate condition. Accurate diagnosis is essential to determine which condition is primary and which may be secondary or situational.

When both conditions genuinely coexist, treatment strategies may need to address each separately. NICE Clinical Knowledge Summaries (CKS) on erectile dysfunction and premature ejaculation emphasise the importance of comprehensive assessment, including medical history, physical examination, and consideration of psychological factors. Your GP may arrange blood tests to exclude underlying conditions such as diabetes or cardiovascular disease that could contribute to erectile dysfunction. Typical investigations include HbA1c or fasting glucose, fasting lipid profile, blood pressure measurement, and cardiovascular risk assessment. If you have symptoms of low libido or fatigue, a morning total testosterone level and thyroid function tests may be appropriate.

In cases where both PE and ED are present, healthcare professionals may consider addressing each condition with its appropriate treatment. This might involve using a PDE5 inhibitor to address erectile function alongside behavioural techniques or, under medical supervision, dapoxetine for premature ejaculation. Combining dapoxetine with PDE5 inhibitors is not a licensed indication and increases the risk of dizziness and orthostatic hypotension (low blood pressure on standing). Such combinations should only be used under close medical supervision after careful assessment of risks and benefits.

It is essential that dapoxetine is never combined with other SSRIs, SNRIs, MAOIs, or other medicines that increase serotonin levels, as this can cause serotonin syndrome, a potentially serious condition. Men should never self-prescribe or combine treatments without consulting their GP or specialist, as this could lead to adverse effects or dangerous drug interactions.

Psychological support, including cognitive behavioural therapy or psychosexual counselling, may play a valuable role in managing both conditions, particularly when anxiety or relationship factors contribute to the difficulties. Your GP can refer you to appropriate NHS sexual health services or specialist psychosexual therapy when needed.

You should be referred to a specialist (urology, endocrinology, or psychosexual services) if:

• First-line treatments have not been effective

• There is suspected hormonal deficiency (hypogonadism)

• You have Peyronie's disease (penile curvature or deformity)

• You have had prostate surgery

• There are complex psychological or relationship factors

• You have other significant medical conditions affecting sexual function

Treatment Options for Erectile Dysfunction in the UK

The NHS and NICE Clinical Knowledge Summaries provide clear pathways for the assessment and management of erectile dysfunction in the UK. First-line treatment typically involves addressing modifiable risk factors and underlying health conditions. Lifestyle modifications are foundational and include:

• Weight management – obesity is strongly associated with ED

• Regular physical exercise – improves cardiovascular health and erectile function

• Smoking cessation – smoking damages blood vessels and impairs erectile function

• Alcohol moderation – excessive consumption can contribute to ED

• Optimising management of chronic conditions such as diabetes, hypertension, and cardiovascular disease

Pharmacological treatment with PDE5 inhibitors remains the mainstay of ED management for most men. Sildenafil, tadalafil, vardenafil, and avanafil are all available in the UK and work by enhancing the natural erectile response to sexual stimulation. These medications differ in their onset of action and duration of effect. For example, sildenafil typically works within 30–60 minutes and lasts approximately 4 hours, whilst tadalafil can remain effective for up to 36 hours. Choice depends on individual preference, lifestyle factors, and tolerability.

Important safety information for PDE5 inhibitors:

• Absolutely contraindicated in men taking nitrates (commonly prescribed for angina), nicorandil, or riociguat, due to the risk of severe, potentially life-threatening hypotension (low blood pressure)

• Use with caution in men taking alpha-blockers (for prostate symptoms or high blood pressure), as the combination can cause significant blood pressure drops. Your doctor will advise on dose separation and monitoring

• Men should always disclose their full medication history to their prescriber

• Common side effects include headache, facial flushing, indigestion, and nasal congestion, which are usually mild and transient

For men who cannot use or do not respond to oral medications, second-line treatments include:

• Intracavernosal injections (alprostadil) – injected directly into the penis

• Topical alprostadil cream – applied to the tip of the penis

• Vacuum erection devices – mechanical devices that draw blood into the penis

• Intraurethral alprostadil – a pellet inserted into the urethra

Third-line treatment, available through specialist urology services, includes penile prosthesis surgery for men who have not responded to other treatments. Access to these treatments on the NHS may vary by region.

Psychological interventions are appropriate when ED has a significant psychological component or when anxiety and relationship factors contribute to the condition. Psychosexual therapy or cognitive behavioural therapy can be accessed through NHS sexual health services or privately.

You should contact your GP if you experience persistent erectile difficulties. Persistent erectile dysfunction warrants cardiovascular risk assessment, as ED can be an early marker of cardiovascular disease, often preceding coronary artery disease by several years. However, sudden-onset erectile difficulties in younger men are more commonly due to psychological factors such as stress, anxiety, or relationship issues.

Seek urgent medical attention if:

• You have an erection lasting more than 4 hours (priapism) – this is a medical emergency requiring immediate treatment to prevent permanent damage

• You develop new penile pain, curvature, or deformity, which may suggest Peyronie's disease

You should see your GP promptly if erectile difficulties are accompanied by:

• Reduced libido, fatigue, or mood changes (which might indicate hormonal or systemic conditions)

• Symptoms of diabetes (increased thirst, frequent urination, unexplained weight loss)

• Chest pain or breathlessness on exertion

Your GP can arrange appropriate investigations, provide evidence-based treatment, and refer to specialist urology, endocrinology, or psychosexual services when necessary. Remember to report any suspected side effects from ED treatments via the MHRA Yellow Card Scheme at yellowcard.mhra.gov.uk or through the Yellow Card app.

Frequently Asked Questions