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Sildenafil

Sildenafil tablets treat erectile dysfunction (ED). Take this prescription-only medication in one singular dose about one hour before sexual activity. Sildenafil tablets widen the penis’s blood vessels, helping to achieve and maintain a stronger, longer-lasting erection. It's suitable for men who are experiencing ED, and contains sildenafil citrate.

  • Treats erectile dysfunction
  • Take about one hour before sex
  • Generic version of Viagra

Buy Sildenafil Online

Sildenafil tablets are a common treatment prescribed for erectile dysfunction. It works by increasing the body’s blood flow to the penis during sexual arousal, helping achieve and maintain an erection more easily.

Buy Sildenafil here at Pharmacy Online. Get your prescription for 100mg, 50mg, or 25mg. Then, simply start a consultation.

When to use Sildenafil

Sildenafil tablets are effective treatments for erectile dysfunction. Taking Sildenafil about one hour before sexual activity can ensure you achieve and maintain an erection, strengthening relationships.

Please note that the medicine only works if you're sexually aroused and should never be taken unless you're planning on sexual activity.

Age Restrictions:

As a medicine for treating erectile dysfunction, Sildenafil tablets are only suitable for males aged 18 and over.

How to Use Sildenafil

Sildenafil should be taken as and when needed, about one hour before sexual activity. Here's how to use it safely and effectively:

  • Food: It's OK to take the erectile dysfunction drug with or without food, but using it after consuming a meal that's high in fat can reduce its effectiveness.
  • Frequency: Never take more than one dose of Sildenafil a day.
  • Dosage: The standard Sildenafil dosage is 50 mg, but your doctor can adjust it depending on your response to the treatment. If you have severe kidney problems, your doctor may start you on 25 mg.
  • Sexual Stimulation: While some erectile dysfunction treatments are spontaneous, Sildenafil will only work when a person becomes sexually aroused.

Always follow your healthcare provider’s guidance for safe and effective use.

When to Avoid Using Sildenafil

If any of the following apply, it's best to avoid Sildenafil and seek other treatment options:

  • You're allergic or sensitive to any of the ingredients.
  • Are currently taking nitrate medications (angina treatments) as it can cause severe blood pressure drops.
  • Use amyl nitrite ("poppers") or another nitric oxide donor, as it can cause severe blood pressure drops.
  • Are taking riociguat, a medicine for high blood pressure in the lungs.
  • Suffer with a heart condition and have been advised to abstain from sexual activity.
  • Have recently experienced a stroke or heart attack.
  • Have low blood pressure (below 90/50 mmHg).
  • Have severe liver problems.
  • Have retinitis pigmentosa - an eye condition.
  • Have ever lost sight in one eye because of NAION (non-arteritic anterior ischaemic optic neuropathy).

Always consult your healthcare provider before using the treatment. They can assess whether Sildenafil is suitable for your needs.

Precautions:

  • Alcohol: Drinking alcohol can temporarily make it harder to get an erection. To get the most from your medicine, do not drink excessive amounts of alcohol before taking Sildenafil.
  • Grapefruit Juice: Grapefruit juice may slightly increase the amount of Sildenafil in your blood.
  • Other Medications: Sildenafil may interact with other medicines. Do not take it with riociguat. Tell your doctor or pharmacist if you take an alpha-blocker (for high blood pressure or an enlarged prostate), HIV medicines called protease inhibitors (such as ritonavir or saquinavir), some antibiotics (such as erythromycin), antifungals (such as ketoconazole or itraconazole), sacubitril/valsartan (for heart failure) or nicorandil (for angina). Please tell your doctor or pharmacist about all your prescription medicines and supplements.
  • Hearing Problems: Sudden hearing loss is rare, but the erectile dysfunction treatment can potentially cause hearing issues.
  • Vision Problems: Sildenafil might cause vision problems, including sensitivity to light and blurred vision.
  • Heart Problems: Sildenafil can cause low blood pressure, which puts people with heart conditions at risk.
  • Priapism Risk: Tell your doctor before taking Sildenafil if you have sickle cell anaemia, leukaemia or multiple myeloma, which can make a prolonged erection (priapism) more likely, or a deformity of the penis or Peyronie's disease.
  • Driving and Operating Machinery: Sildenafil can cause dizziness or blurred vision in some people. If you experience these side effects, avoid driving or operating machinery.

Ingredients

Sildenafil 50mg tablets contain the following ingredients:

  • Active Ingredient: Sildenafil citrate
  • Inactive Ingredients: These depend on the maker of your tablets. Your pack may come from any of the makers below, and the leaflet inside your pack is the one that applies to your tablets.
    • Amarox: microcrystalline cellulose, calcium hydrogen phosphate (anhydrous), croscarmellose sodium, magnesium stearate. Film coat: polyvinyl alcohol (part hydrolysed), titanium dioxide (E171), macrogol, talc, indigo carmine aluminium lake (E132), hypromellose and triacetin. No lactose.
    • Milpharm: calcium hydrogen phosphate, microcrystalline cellulose, croscarmellose sodium, colloidal anhydrous silica, magnesium stearate. Film coat: lactose monohydrate, hypromellose, titanium dioxide (E171) and triacetin.
    • Krka: microcrystalline cellulose (E460), calcium hydrogen phosphate, croscarmellose sodium, hypromellose (E464), magnesium stearate (E470b). Film coat: lactose monohydrate, hypromellose (E464), titanium dioxide (E171) and triacetin (E1518).
    • Umedica: calcium hydrogen phosphate, microcrystalline cellulose, croscarmellose sodium, colloidal silica, magnesium stearate. Film coat: hypromellose (E464), indigo carmine (E132), lactose monohydrate, titanium dioxide (E171) and triacetin (E1518).
    • Dr. Reddy's: microcrystalline cellulose, calcium hydrogen phosphate dihydrate, croscarmellose sodium, hydroxypropyl cellulose, magnesium stearate. Film coat: hypromellose (E464), lactose monohydrate, triacetin (E1518), titanium dioxide (E171) and indigo carmine lake (E132).
    • Sandoz: calcium hydrogen phosphate anhydrous, microcrystalline cellulose, copovidone, croscarmellose sodium, magnesium stearate, saccharin sodium and indigo carmine aluminium lake (E132). No lactose.
  • Lactose: Tablets from some makers contain lactose. If you have been told by your doctor that you have an intolerance to some sugars, talk to our pharmacist before ordering.

There are possible risks of side effects when taking Sildenafil for erectile dysfunction, as with any medication. Most side effects are quite mild and subside over time. Others may be more serious and should be reported to your GP immediately if you experience them when using Sildenafil. Please get in touch with a member of our team if you are worried about any potential side effects of Sildenafil.

Very common side effects of Sildenafil (may affect more than 1 in 10 people):

  • Headaches

Common side effects of Sildenafil (may affect up to 1 in 10 people) may include:

  • Stuffy nose
  • Flushing
  • Dizziness
  • Nausea

Uncommon side effects of Sildenafil (may affect up to 1 in 100 people) may include:

  • Runny nose
  • Nosebleeds
  • Feeling hot
  • Muscle pain

Where side effects are more serious, you should immediately stop taking Sildenafil and report these to your GP urgently. More serious side effects of Sildenafil may include:

  • Priapism after taking Sildenafil (an erection that will not go away). If your erection persists for more than 4 hours, seek immediate medical help. Priapism can lead to permanent damage to your penis.
  • Sudden loss of vision, either in both or one eye. This sudden vision loss can indicate a serious eye problem named non-arteritic anterior ischaemic optic neuropathy.
  • Sudden hearing loss or a decrease in hearing. Some may also experience tinnitus (ringing in the ears) or dizziness.
  • An allergic reaction - sudden wheeziness, difficulty breathing or dizziness, or swelling of the eyelids, face, lips or throat.
  • Chest pain. If this happens during or after sex, get into a semi-sitting position and try to relax. Do not use nitrates to treat your chest pain.
  • A serious skin reaction - severe peeling and swelling of the skin, blistering of the mouth, genitals and around the eyes, and fever.
  • Seizures or fits.
How long do Sildenafil tablets take to work?

Take Sildenafil about one hour before sexual activity. It normally takes between half an hour and one hour to work, and it may take longer if you take it with a heavy meal.

Sildenafil 25mg tablets can take different amounts of time to produce the desired effect depending on several factors. These can include the level of Sildenafil doses, such as 25mg, 50mg, or 100mg, as well as diet and alcohol consumption.

Is Sildenafil available over the counter?

No. You'll need a private prescription or visit your GP to access Sildenafil. Viagra Connect (50 mg sildenafil) is a pharmacy medicine that can be supplied without a prescription after a pharmacist assessment, but it is a separate product.

What is the recommended dosage of Sildenafil?

Most people start on a dose of 50 mg, but your doctor may recommend 25 mg, or a higher dose up to a maximum of 100 mg, if Sildenafil doesn't have the desired effects.

How long does the effect of Sildenafil last?

It depends on how your body responds to the treatment and whether you're sexually aroused.

When I buy Sildenafil online, how regularly can I take it?

Sildenafil 25mg tablets are taken only when needed to treat erectile dysfunction, and never more than once a day. Do not take more than one erectile dysfunction medication treatment in 24 hours.

What happens if Sildenafil tablets don't work for erectile dysfunction?

If Sildenafil does not help you get an erection, or your erection does not last long enough to complete sex, tell your doctor. Depending on how well it works and how you get on with it, your prescriber may change the dose (between 25 mg and 100 mg) or suggest an alternative erectile dysfunction treatment.

Alternative erectile dysfunction treatments include Tadalafil (Cialis) and Vardenafil (Levitra).

Can I buy Sildenafil online if I have heart problems?

If you suffer from heart problems or a heart condition, you should take caution before using Sildenafil tablets and other erectile dysfunction medications. A Sildenafil tablet has the potential to put the heart under increased strain as a result of its vasodilative effects. Although Sildenafil tablets primarily target the penis’s blood vessels, this medication can also affect the heart’s blood vessels.

If you have heart problems, please consult your GP before taking or buying Sildenafil.

When to take Sildenafil 25mg tablets?

As a single-dosage erectile dysfunction medication, you take Sildenafil only when needed, and never more than once a day. You should not take more than one Sildenafil tablet, or other erectile dysfunction medication, within the same 24-hour period.

Who shouldn't buy Sildenafil online for erectile dysfunction?

Whether Sildenafil is suitable will depend on individual circumstances, existing conditions, symptoms, and their severity. If this is the case, speak to one of our experts.

Is Sildenafil safe for long-term use?

Please attend regular medical reviews to ensure your doctor can identify any complications.

Can older adults take sildenafil?

Yes, older adults can use Sildenafil. Please consult a doctor before beginning treatment if you have any health conditions.

Can I take Sildenafil every day?

No. Sildenafil is not a daily treatment. Take it only when you plan to have sex, and never more than once a day.

What should I do if I take too much Sildenafil?

If you take too much Sildenafil, you may get more side effects, and they may be more severe, such as headache, flushing, dizziness, indigestion, a stuffy nose and changes in your vision. Doses above 100 mg do not work any better. Contact your doctor if you take more tablets than you should.

Can Sildenafil be used for conditions other than erectile dysfunction?

No. These Sildenafil tablets are licensed only to treat erectile dysfunction in men.

How should I store Sildenafil?

Keep Sildenafil away from pets and children. There are no special storage conditions, but follow the instructions on your pack.

Are there alternatives to Sildenafil?

Yes, there are plenty of erectile dysfunction drugs available, and the one you choose depends on whether you have any existing health conditions and the severity of your ED. Popular medications include tadalafil (Cialis), vardenafil (Levitra), and avanafil (Spedra).

Can Sildenafil be used alongside other treatments for erectile dysfunction?

No. Do not use Sildenafil with any other treatment for erectile dysfunction, whether it is a tablet or one used on the penis.

Leaflets

Before taking Sildenafil tablets for erectile dysfunction or any medications, it is essential always to read the patient information leaflet.

This provides essential information on side effects, potential interactions, and how to take Sildenafil properly. If you have any questions or need advice, please contact our UK-registered online pharmacy today.

Sildenafil Patient Information Leaflet

Several makers produce Sildenafil tablets, and the link above is one maker's leaflet (Milpharm). The leaflet inside your pack is the one that applies to your tablets.

Umar Razzaq, MPharm | University of Strathclyde, Clinical Pharmacist.
Content Written by:Umar RazzaqMPharm | GPhC Reg: 2064448 | University Of Strathclyde
Date Written:12/06/2026
Role:Clinical Pharmacist
Nish Fayyaz, MPharm | University of Strathclyde, Pharmacist.
Medically Reviewed By:Nish FayyazMPharm | GPhC Reg: 2225257 | University Of Strathclyde
Date Checked:12/06/2026
Role:Pharmacist
Fully inspected and regulated service
UK registered pharmacy
Approved UK-licensed treatments
Discreet next day delivery