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Sildenafil

Order Your Prescription For Sildenafil

Sildenafil is an affordable treatment for erectile dysfunction, that is effective for 74% of men who try it. Sildenafil starts working within an hour of taking it, and lasts for up to 6 hours. Sildenafil is the generic version of Viagra, and works in the same way at a lower cost.

You can use your Superdrug Online Doctor prescription to buy Sildenafil at any pharmacy in Ireland.

Use our online assessment to order. A Superdrug Online Doctor will complete your prescription and we'll post it to you.

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More Information

Sildenafil:

  • is a tablet that can help you get and keep erections 
  • is the generic version of the branded erectile dysfunction treatment, Viagra
  • contains sildenafil citrate, the same active ingredient in Viagra
There are a few different manufacturers of Sildenafil, including Teva. There are also some kinds of Sildenafil that aren’t approved in the Ireland, like Sildamax.

What strengths of Sildenafil are there?

Sildenafil comes in 3 strengths, 50mg, 25mg, and 100mg:

  • 50mg is the dosage most people start on and it works for most men who try it
  • 25mg is the dosage you could try if you’ve already tried 50mg and it worked but you had some mild side effects – 25mg might improve these side effects
  • 100mg is the dosage you could try if you tried 50mg and you didn’t get any side effects but you also didn’t see the results you hoped for – 100mg can work when 50mg doesn’t
Make sure to check with a doctor before switching the dosage of any medication
If you’ve never used Sildenafil before and you’re not sure which dose to try, we recommend 50mg.

How does Sildenafil work?


Sildenafil works the same way as Viagra. It improves the blood flow to your penis, making it easier for you to get an erection that’s hard enough for sex if you’re sexually aroused. 

How to take Sildenafil

Taking Sildenafil is easy, just like any other tablet you swallow:

  • Before taking Sildenafil, read the patient information leaflet that comes with your medication
  • Take Sildenafil one hour before you want to have sex
  • Swallow your tablet whole, with water if needed
  • Do not take Sildenafil more than once every 24 hours
  • For the best results, avoid eating heavy meals or drinking alcohol before using Sildenafil 
  • You may need to take Sildenafil on up to 8 times (on different days) before you see the full effect

How long does Sildenafil last?

  • Sildenafil starts working around 30 to 60 mins after you take it
  • Sildenafil normally lasts around 4 to 6 hours
  • Sildenafil may take longer to work if you eat a heavy meal or drink alcohol beforehand
  • If you want a medication that lasts longer, you could think about trying Cialis
  • If you want a medication that works quicker, Spedra starts working in just 15 and Cialis Daily works constantly so there’s no waiting time

Does Sildenafil work for women?

Sildenafil is not proven to work for women, and it may be dangerous to use. It’s not clear if it improves sex drive or pleasure during sex either. It is illegal for women to buy Sildenafil in the Ireland. 

Sildenafil vs Viagra

  • Pfizer patented Sildenafil after it was created, selling it exclusively under the brand name Viagra
  • This patent expired in 2013 and since then other manufacturers have been able to make and sell generic Sildenafil
  • Sildenafil is a generic medication so it can be manufactured by anyone, but Viagra is a Pfizer brand, so only they can make it
  • In 2017 Pfizer patented the first over-the-counter form of Sildenafil – Viagra Connect

Sildenafil is the generic version of Viagra. This means that they work in exactly the same way, and are just as effective. The only difference between this medications is the brand name on the box, and the price of the medication. Because Sildenafil is a generic medication, it is usually available at a lower price than branded Viagra.

If you’re not sure which to choose, remember they both have the same active ingredient and both are safe as long as a doctor approves treatment for you. We don’t recommend one over the other.

Sildenafil is an effective treatment, but it doesn’t work for everyone:

  • On average, patients who used Superdrug Online Doctor to order Sildenafil treatment rate it 4.6 out of 5 stars on Trustpilot.com

Sildenafil can cause some side effects and it may react with other medication you’re taking. For full safety information, please read the patient information leaflet that comes with your medication. 

Side effects of Sildenafil

Less than 2% of people appear to get side effects when taking Sildenafil. If you do get side effects they are likely to be mild. If you think you’re having Sildenafil side effects, talk to your doctor. 

Common side effects:

  • headache
  • nausea
  • indigestion
  • blocked nose
  • facial flushing
  • hot flushes
  • eyes problems, such as blurred vision
  • dizziness

Uncommon side effects:

  • vomiting
  • skin rash
  • eyes irritation/pain
  • bloodshot eyes
  • seeing flashes of light
  • visual brightness
  • sensitivity to light
  • rapid heartbeat
  • muscle pain
  • feeling sleepy or tired
  • blocked sinuses
  • upper abdominal pain
  • feeling hot
  • nosebleeds
  • arm or leg pain
  • blood in urine
  • watery eyes
  • Rare side effects:
  • irregular heartbeat
  • heart attack
  • stroke
  • fainting
  • numb mouth
  • temporary reduced blood flow to brain
  • tightening in the throat
  • double vision
  • swelling of the eye or eyelid
  • abnormal sensations in the eye
  • spots in your vision
  • dilated pupils
  • discolouring of the whites of the eyes
  • bleeding from the penis
  • blood in semen
  • dry nose
  • irritability
  • swelling on the inside of the nose
  • sudden loss of hearing

Serious side effects:

If you experience the following, you should stop taking Sildenafil and seek medical help immediately:

  • allergic reaction – symptoms include breathing difficulties, dizziness, swelling of face, lips, or tongue 
  • chest pains

Drug interactions

The following drugs can interact with Sildenafil. You should make sure you tell your doctor if you are taking any of the following:

  • nitrates
  • nitric oxide donors (“poppers”)
  • protease inhibitors (used to treat HIV)
  • alpha-blocker therapy
  • riociguat used for pulmonary hypertension

Herbal or complementary remedies could also interfere with Sildenafil and potentially cause side effects. If you are taking any herbal remedies, you should speak to your doctor to make sure there isn’t a risk of interaction.

Pre-existing conditions

Sildenafil is not suitable for some men who have certain medical conditions. For example, you may not be suitable for Sildenafil treatment if you have:

  • a serious heart or liver problem
  • take nitrates for a chest pain
  • recently had a stroke or a heart attack
  • low blood pressure
  • a rare inherited eye disease
  • You should also let your doctor know if you have:
  • sickle cell anaemia
  • Peyronie’s disease or a penis deformity
  • a heart problem
  • a stomach ulcer
  • a bleeding problem like haemophilia
There are other treatment options for erectile dysfunction other than Viagra and Sildenafil. Please check out our Erectile Dysfunction Treatment page for more information.