ERECTIONS ∙ 1 minute read

The common side effects of taking sildenafil

By Duncan Fisher

Sildenafil is routine medication for erectile dysfunction. But like many medications, there are some common side effects to be aware of.

The active ingredient in sildenafil belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors. It works by helping to relax the blood vessels in your penis, allowing blood to flow in when you’re sexually aroused, and produce an erection.

Sildenafil has been available for a long time, and has been well studied. Overall, it has shown itself to be an effective and well-tolerated treatment for erectile dysfunction in men of all ages.

Like any medication, however, sildenafil can sometimes cause side effects. Not everybody gets them, and most of the side effects reported with sildenafil are fairly mild and don’t last long.

The most common side effect is headache, affecting about 1 in 10 people.

Slightly less common side effects include:  

  • nausea
  • facial flushing
  • suddenly feeling hot
  • indigestion
  • blurred or colour-tinged vision
  • stuffy nose
  • dizziness

Uncommon side effects, which may affect only 1 in 100 people include:

  • vomiting
  • skin rash
  • eye irritation
  • seeing flashes of light, or being sensitive to light
  • rapid heartbeat
  • high blood pressure
  • low blood pressure
  • muscle pain
  • feeling sleepy
  • reduced sense of touch
  • vertigo
  • ringing in the ears
  • dry mouth
  • stuffy sinuses, or runny nose
  • nosebleed
  • heartburn
  • blood in your urine
  • pain in your arms or legs
  • feeling really hot
  • feeling really tired

There are rare reports of serious adverse effects and allergic reactions that have been related to sildenafil use. There are also certain conditions and which make sildenafil or tadalafil inappropriate, unsuitable or unsafe to take. This also goes for certain other medications which can interact with sildenafil and tadalafil. If you’re in any doubt, it’s best to speak to your doctor. Once you have the medication, as with anything you’re prescribed, you should thoroughly read through the patient information leaflet that comes with it before you start taking it.