Description
What is Sildenafil?
Sildenafil is a prescription treatment for erectile dysfunction (ED) in men. It contains sildenafil citrate, a clinically proven medicine that helps increase blood flow to the penis, making it easier to achieve and maintain an erection when sexually aroused.
Sildenafil is the generic version of Viagra® and contains the same active ingredient. Most men find sildenafil starts working within 30 to 60 minutes and remains effective for up to 4 hours.
Available Strengths
Sildenafil 25mg
Sildenafil 25mg is the lowest available strength and may be suitable for men who are more sensitive to sildenafil or those who have experienced side effects with higher doses. It may also be recommended for certain patients based on their age, medical history or other medications they take.
Sildenafil 50mg
Sildenafil 50mg is the usual recommended starting dose for most men with erectile dysfunction. It provides an effective balance between efficacy and tolerability and is often the first strength prescribed following an assessment.
Sildenafil 100mg
Sildenafil 100mg is the highest available strength and may be recommended for men who do not achieve satisfactory results with the 50mg dose. This strength should only be used when advised by a prescriber.
Our clinicians will recommend the most appropriate strength based on your medical history, current medications and response to treatment.
How Does Sildenafil Work?
Sildenafil belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors. It works by relaxing blood vessels and increasing blood flow to the penis during sexual stimulation.
Sildenafil does not increase sexual desire and only works when sexual arousal is present.
Who Can Use Sildenafil?
Sildenafil may be suitable for:
- Men aged 18 years and over
- Men experiencing erectile dysfunction
- Men seeking a clinically proven ED treatment
- Men looking for an effective treatment that is taken only when needed
- Men seeking an alternative to branded Viagra®
Who Should Not Use Sildenafil?
Sildenafil may not be suitable if you:
- Take nitrate medicines for chest pain or heart conditions
- Use nitric oxide donors or recreational drugs known as “poppers”
- Have certain serious heart, liver or blood pressure conditions
- Have been advised to avoid sexual activity
- Have previously experienced an allergic reaction to sildenafil or any of the ingredients
Our prescribing team will assess your suitability before treatment is supplied.
How to Take Sildenafil
- Take one tablet approximately 30 to 60 minutes before sexual activity
- Swallow the tablet whole with water
- Do not take more than one dose in a 24-hour period
- Follow the advice provided by your prescriber
Sildenafil can be taken with or without food. However, a heavy or high-fat meal may delay how quickly it starts working.
Excessive alcohol consumption may reduce the effectiveness of treatment and increase the likelihood of side effects.
Benefits of Sildenafil
- Clinically proven treatment for erectile dysfunction
- Available in 25mg, 50mg and 100mg strengths
- Contains the same active ingredient as Viagra®
- Taken only when needed
- Effective for up to 4 hours
- Available through our confidential online consultation service
Common side effects include:
- Headache
- Facial flushing
- Nasal congestion
- Dizziness
- Indigestion
- Visual disturbances such as blurred vision or changes in colour perception
Most side effects are mild and temporary.
Always read the Patient Information Leaflet before taking this medication.
Seek immediate medical attention if you experience chest pain, sudden loss of vision or hearing, or an erection lasting longer than 4 hours.
Frequently Asked Questions
Which sildenafil strength should I choose?
Most men begin treatment with sildenafil 50mg. Depending on how well the medication works and whether side effects occur, your prescriber may recommend reducing the dose to 25mg or increasing it to 100mg.
How long does sildenafil take to work?
Sildenafil usually starts working within 30 to 60 minutes. Sexual stimulation is required for the medicine to be effective.
How long does sildenafil last?
Sildenafil can remain effective for up to 4 hours, although individual responses vary.
Can I take sildenafil with food?
Yes. Sildenafil can be taken with or without food. A large or high-fat meal may delay the onset of action.
Can I drink alcohol while taking sildenafil?
Small amounts of alcohol are unlikely to cause problems. However, excessive alcohol consumption may make it more difficult to achieve an erection and can reduce the effectiveness of treatment.
Is sildenafil the same as Viagra®?
Yes. Sildenafil is the generic version of Viagra® and contains the same active ingredient. It works in the same way and is held to the same quality, safety and effectiveness standards.
Do I need a GP prescription for sildenafil?
No. Sildenafil is a prescription-only medicine but you do not need a GP prescription for it. Our prescribing clinicians can assess and prescribe sildenafil to eligible patients.
Online Erectile Dysfunction Consultation
Before treatment can be supplied, you will need to complete a short online medical questionnaire.
One of our qualified prescribing clinicians will review your information to ensure sildenafil is safe and appropriate for you.
If approved, your treatment will be dispensed by The Kingston Pharmacy team and delivered in discreet packaging directly to your door via Royal Mail. We also offer in-store collection.





