Sildenafil 50mg is the usual recommended dose for many adults using sildenafil for erectile dysfunction (ED). It is normally taken when needed, approximately one hour before sexual activity, and it should not normally be taken more than once in a day. The dose may be reduced to 25mg or increased to 100mg only after a prescriber reviews effectiveness, side effects, other medicines and relevant health conditions.
The medicine helps the normal erection response during sexual stimulation; it does not create sexual desire or cause an automatic erection. A large or high-fat meal can delay how quickly it starts to work, and substantial alcohol intake can make it harder to get an erection. This page explains the 50mg strength without replacing an individual prescribing decision.
Sildenafil 50mg contains sildenafil, a phosphodiesterase type 5 (PDE5) inhibitor licensed for erectile dysfunction. During sexual stimulation, sildenafil supports the natural chemical signals that relax blood vessels in the penis, allowing more blood to enter the erectile tissue. This can make it easier to get and maintain an erection when arousal is present.
The 50mg tablet is not a different medicine from the 25mg or 100mg strengths; it contains the same active ingredient in a different amount.
For a deeper explanation of the mechanism, see how sildenafil works.
UK product information describes 50mg as the recommended dose for many adults with ED. It gives a practical starting point from which a prescriber can judge response and tolerability. “Common starting dose” does not mean the strength is automatically right for every person.
A lower dose may be considered in some people because of side effects, interacting medicines or health conditions that can increase sildenafil exposure.
A higher dose may be considered when 50mg has not provided an adequate response and the person is suitable for an increase. The maximum recommended dose for ED is 100mg, and self-escalation is not appropriate.
Take the dose exactly as prescribed or directed by the clinician who assessed you. The licensed guidance for ED is to take sildenafil approximately one hour before sexual activity. Swallow the tablet with water.
Sildenafil can be taken with or without food, but food - especially a large or high-fat meal - can delay the time it takes to start working.
Do not take more than one sildenafil dose in a day unless a clinician is treating a different condition under a specialist regimen. Do not combine it with tadalafil, vardenafil, avanafil or another sildenafil-containing medicine unless a clinician has specifically instructed you to do so.
The broader sildenafil dosage guide explains how 25mg, 50mg and 100mg are selected and adjusted.
Response varies between individuals. Timing, a heavy meal, alcohol, sexual stimulation, anxiety, cardiovascular health, diabetes, other medicines and the underlying cause of ED can all affect the result.
One disappointing attempt does not prove that the dose is wrong, but repeated lack of effect should be reviewed rather than answered by taking extra tablets.
If the medicine repeatedly gives an inadequate response despite correct use, review why sildenafil may not be working and speak to a prescriber.
The next step may involve correcting timing or use, checking interactions or health factors, reviewing the dose within the licensed range, or considering another treatment.
For many people, the main useful treatment window is around four hours. The effect gradually reduces over time, and clinical data show that sildenafil can still support an erection with sexual stimulation four to five hours after a dose in some people.
This does not mean an erection should last for hours. The dose strength and the duration are different questions. Increasing the dose does not reliably make sildenafil last longer.
For a dedicated duration explanation, see how long sildenafil lasts.
Common side effects can include headache, flushing, indigestion, a blocked nose, dizziness, nausea and temporary visual disturbance. These do not affect everyone, and their severity varies.
Persistent or troublesome symptoms should be discussed with a healthcare professional.
Seek urgent medical help for serious symptoms such as chest pain, a severe allergic reaction, sudden loss or major change of vision, or a painful erection lasting longer than four hours.
If chest pain occurs during or after sex after taking sildenafil, seek urgent medical help and tell the clinician that sildenafil was taken. Do not use nitrate medicines to treat the chest pain.
Sildenafil must not be taken with nitrate medicines or nitric-oxide donors such as amyl nitrite because the combination can cause a dangerous fall in blood pressure. Riociguat is also contraindicated.
The medicine may be unsuitable for some people with very low blood pressure, recent serious cardiovascular events, severe liver disease, certain inherited retinal conditions, previous non-arteritic anterior ischaemic optic neuropathy (NAION), or a condition in which sexual activity is medically inadvisable.
This is not an exhaustive suitability list. Tell the prescriber about all medicines, heart or blood-pressure problems, kidney or liver disease, eye conditions and previous reactions.
The specialist page on when sildenafil may not be suitable provides more context, but a clinical assessment remains necessary.
The three common ED tablet strengths contain the same medicine. The main difference is the amount of sildenafil in each tablet and the circumstances in which each strength may be considered.
| Strength | Typical role | Main consideration |
|---|---|---|
| 25mg | Lower dose | May be selected when reduced exposure is appropriate or side effects, health conditions or interacting medicines are a concern. |
| 50mg | Usual recommended dose for many adults | Provides a common starting point from which response and tolerability can be reviewed. |
| 100mg | Maximum recommended ED dose | May be considered when a lower dose has not produced an adequate response and the higher dose is clinically suitable. |
Do not choose a strength by price, body size, another person’s experience or an assumption that more medicine must work better.
The aim is to use the lowest suitable dose that provides an adequate response without unacceptable side effects.
If you want to compare the licensed strengths in detail, use the sildenafil dosage guide.
Sildenafil is a prescription-only medicine in the UK. Supply through Medicina is consultation-led: a UK-registered prescriber reviews the medical information provided and decides whether sildenafil and a particular strength are suitable.
Completing a consultation does not guarantee a prescription or supply.
For current strengths, quantities and service information, review the current Sildenafil treatment options.
The treatment page is the transactional owner for availability and pricing; this 50mg page remains a strength-specific medical information page.
Sildenafil 50mg is a common recommended dose for erectile dysfunction, but it is not automatically right for everyone.
Use it only as directed, allow roughly an hour before sexual activity, do not take it more than once in a day for ED, and do not change strength without professional advice.
If the dose is ineffective, causes side effects or raises safety concerns, a prescriber can review how it is being used and whether a lower dose, higher dose within the licensed range, another ED treatment or further assessment is appropriate.
For a broader overview of available routes, see erectile dysfunction treatments.
Written by Medicina Pharmacy.
Medically reviewed by Yasmeen Akthar - Superintendent Pharmacist (GPhC 2058731); Saleh Ahmed - Independent Prescriber & Advanced Practitioner (GPhC 2065382); and Mohammed Shajan Ali - Independent Prescriber (GPhC 2067785).
This page provides general information about sildenafil for erectile dysfunction and is not personal medical advice. Sildenafil is a prescription-only medicine and may not be suitable for everyone.
Use it only as directed by a prescriber, pharmacist, label and patient leaflet.
If you have severe or urgent symptoms, seek appropriate urgent medical care. Product availability, price and service terms can change.
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