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Erectile Dysfunction Treatment
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Sildenafil 25mg 4 Tablets

Sildenafil tablets (25mg, 50mg, 100mg)

Sildenafil tablets (25mg, 50mg, 100mg) Product information

£5.89 (£1.47 per tablets)

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Quantity

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Our Prices
25mg 50mg 100mg
4 tablets £5.89 £8.19 £8.19
8 tablets £9.49 £13.79 £14.89
16 tablets £14.98 £22.79 £25.85
32 tablets £31.99 £41.35 £41.98
64 tablets £40.98 £57.49 £62.98

What is Sildenafil?

Sildenafil tablets (25mg, 50mg, 100mg) are a trusted treatment for erectile dysfunction (ED). They help increase blood flow to the penis during sexual stimulation, making it easier to get and keep an erection firm enough for sex.

Available in the UK after an online consultation, Sildenafil is taken when needed, usually about one hour before sex, with effects lasting for up to 4 hours. Many men find that treatment helps them feel more confident about intimacy again.

Complete a short online consultation to check whether Sildenafil pills are suitable for you, and get back to feeling like yourself again.

The manufacturer of the product supplied may vary. Please read the patient information leaflet that is provided with the product. If you would like a specific brand please do contact our customer services team.

Product Information for Sildenafil tablets (25mg, 50mg, 100mg)

About Sildenafil

The Sildenafil film-coated tablet is the generic version of the well-known Viagra brand of ED tablets. This means they contain the same active ingredient (Sildenafil). They’re available in strengths of 25mg, 50mg and 100mg, and in quantities of 4, 8, 16, 32 or 64 tablets.  

Sildenafil key features

Sildenafil is often known as an ‘on-demand’ treatment because it only needs to be taken around 1 hour before sex, rather than daily.

  • Oral tablet

  • Works in as little as 30 minutes

  • Lasts up to 4 hours

Read more about taking Sildenafil in the Directions for Use section and remember to always read the Patient Information Leaflet that comes with the medication. 

How does Sildenafil work for Erectile Dysfunction?

Sildenafil belongs to a group of medicines called PDE5 inhibitors, which treat erectile dysfunction by increasing blood flow to the penis during sexual stimulation.

Normally, an enzyme called PDE5 breaks down the chemical signals that allow erections to happen. Sildenafil blocks this process so blood vessels stay relaxed for longer, helping you achieve and maintain an erection when sexually aroused.

Importantly, Sildenafil does not increase libido or cause automatic erections. It works only when you are sexually stimulated.

Am I eligible for Sildenafil tablets?

Sildenafil film-coated tablets are a prescription-only medication. You might be suitable if you meet the criteria below, however a doctor will complete a full clinical review of your completed online assessment before issuing a prescription.

  • Male (those assigned male at birth)

  • Aged 18 or over

There are several factors where Sildenafil may not be an appropriate treatment, including if:

  • You take nitrates for a heart condition. These are usually tablets or capsules called Isosorbide Mononitrate or Nicorandil (a medicine very similar to a nitrate) but can be called by other names

  • You use poppers

  • You have angina or have ever been given a spray that goes under your tongue to help chest pain

  • You have had a heart attack or stroke within the last six weeks

  • You have a condition called Peyronie’s or your penis has a bend when erect

  • You, or anyone in your family, has a history of eye disease, including retinitis pigmentosa or non-arteritic anterior ischaemic optic neuropathy (NAION)

  • You have liver or kidney problems

  • You have sickle-cell disease, multiple myeloma, or leukaemia

  • You have a stomach ulcer  

  • You have low blood pressure

  • You have uncontrolled high blood pressure

Our expert team are on-hand to have a confidential and judgement-free chat about any concerns or finding the right treatment path. Call us on 01295 262925 or email help@oxfordop.co.uk

Sildenafil tablets (25mg, 50mg, 100mg) reviews

How to use Sildenafil tablets (25mg, 50mg, 100mg)

Sildenafil film-coated tablets come in strengths of 25mg, 50mg and 100mg. They’re prescription-only and should always be taken as directed.

Make sure to thoroughly read the Patient Information Leaflet that comes with your medication.

How to take Sildenafil

Sildenafil is often known as an “on-demand” erectile dysfunction treatment because it’s taken before sex rather than every day. It is taken as a pill swallowed with water around one hour before sex. For best results, you should try to:

  • Take Sildenafil on an empty stomach if possible

  • Allow time for sexual stimulation

  • Avoid heavy meals immediately beforehand

Always follow the instructions provided by your prescriber and read the Patient Information Leaflet supplied with your medication.

When should I take Sildenafil?

Sildenafil pills are usually taken around 30 to 60 minutes before sex. Taking them ahead of time allows the medicine to start working so your body is better able to respond to sexual stimulation.

Some men notice they can get an erection firm enough for sex sooner than this. How quickly Sildenafil works can vary depending on factors such as recent meals, metabolism, dose strength, and general health. Taking it on an empty stomach may help it work more quickly.

If you don’t time it perfectly, don’t worry. The effects of Sildenafil typically last for up to 4 hours. You won’t have an erection for this entire time, but it does mean your body is better able to respond to sexual stimulation within that window.

What Sildenafil dosage should I start with?

Most men start with Sildenafil 50mg tablets, which work well for many people.

Depending on how well this dose works for you and whether side effects occur, it may be reduced to 25mg or increased to 100mg. This is the maximum amount of Sildenafil you should take daily. Exceeding this dose doesn’t improve effectiveness, but it does increase the risk of side effects.

The right dose depends on how your body responds and your general health, which is why treatment is always reviewed as part of your consultation.

How long does Sildenafil take to work?

You should take your dose of Sildenafil up to an hour before intercourse and it should start to work in around 30 minutes. It requires sexual stimulation to work.

How long does Sildenafil last?

The effects of Sildenafil typically last for 4 hours. This doesn’t mean that you’ll have a constant erection during that time. Instead, it offers a window in which it becomes easier to get an erection when you’re sexually stimulated.

How often should I take Sildenafil?

The recommended maximum dosing frequency is once daily. As the standard dose for most men is 50mg, it is recommended to only take 50mg in 24 hours. However some men may require a higher dose. In either case, you should not take more than 100mg in a 24-hour period.

Sildenafil is not licensed for daily use and is intended to be taken on an “as needed” basis. This means it should be taken 30 to 60 minutes before sexual intercourse, not every day. Taking Sildenafil daily is not recommended and may increase the likelihood of adverse effects.

If you’re considering a daily treatment, Tadalafil may be a good fit for you. Always talk to your prescriber before increasing your dose, frequency or switching treatments.

Side effects of Sildenafil tablets (25mg, 50mg, 100mg)

Below we’ve listed some of the ‘Common’ side effects of Sildenafil tablets. You should always read the Patient Information Leaflet that comes with your medication. A copy of this will also be in the medication packaging or box.

Common side effects (may affect up to 1 in 10 people)

  • Headaches

  • Flushing (red and/or warm skin on the upper body, often on the face)

  • Stuffy nose

  • Upset stomach

  • Nausea

  • Dizziness

The side effects listed below are more serious, and you should stop taking Sildenafil, and get medical help immediately.

  • An erection that will not go away (priapism). If you have an erection that lasts more than 4 hours, seek medical help immediately. Priapism can permanently damage your penis.

  • Sudden vision loss in one or both eyes. Sudden vision loss in one or both eyes can be a sign of a serious eye problem called non-arteritic anterior ischemic optic neuropathy (NAION). Stop taking Sildenafil and get medical help right away if you have sudden vision loss in one or both eyes.

  • Sudden hearing decrease or hearing loss. Some people may also have ringing in their ears (tinnitus) or dizziness. If you experience these symptoms, stop taking Sildenafil and contact a doctor right away.

If you would like to talk to our Healthcare Advisors about any concerns around side-effects please call us on 01295 262925 or email help@oxfordop.co.uk.

Frequently Asked Questions
Patient Information Leaflet

Important - Before taking any medication, it is always important to read the Patient Information Leaflet (PIL)

Sildenafil tablets (25mg, 50mg, 100mg) - Patient Information Leaflet

References
  1. NHS - Erectile Dysfunction

  2. NHS - Sildenafil

  3. NHS - Getting medicines safely online

  4. GPhC - Buying medicines safely online

Message From Our Pharmacist

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Authored on February 10, 2026

Reviewed on February 10, 2026

Kiran Jones

Kiran Jones - MPharm, MRPharmS

Pharmacist / Medical Content Writer

GPhC Number: 2071585