Skip to main content

Common questions about sildenafil

How does sildenafil work?

Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors.

It works if you have erection problems by temporarily increasing blood flow to your penis when you get sexually excited.

It works in pulmonary hypertension by relaxing blood vessels in your chest. This increases the blood supply to your lungs and reduces the workload of your heart.

How well does it work for erection problems?

Sildenafil works well for erectile dysfunction.

If sildenafil does not work for you, it may be because:

  • you have not waited long enough after taking it before trying to have sex
  • you have waited too long after taking it to have sex
  • the dose is not high enough
  • you're not sexually aroused
Are there any long-term side effects?

Sildenafil is safe to take for a long time.

There do not seem to be any lasting harmful effects from taking it for many months and years.

How does it compare to other medicines that can treat erection problems?

If sildenafil does not work, there are other tablets you could try that work in a similar way, such as:

  • tadalafil (Cialis) – can be taken up to 36 hours before sex
  • avanafil (Spedra) – can be taken up to around 4 hours before sex
  • vardenafil (Levitra) – can be taken up to around 4 hours before sex

You could also try a medicine called alprostadil. This is a synthetic hormone that helps to stimulate blood flow to the penis.

Alprostadil comes as:

  • an injection directly into your penis
  • a small pellet placed inside your urethra (the tube that carries pee from your bladder to the tip of your penis)

If you cannot get erections because of a hormonal problem, your GP may refer you to an endocrinologist (who specialises in the treatment of hormonal problems).

You may benefit from treatment using injections of synthetic hormones to restore your hormone levels to normal.

Are there other treatments for erectile dysfunction?

Other treatments for erectile dysfunction include:

  • a vacuum pump
  • psychological treatments
  • penile implants
  • pelvic floor muscle exercises
Is there a herbal Viagra?

There are lots of treatments that claim to be a "herbal Viagra". In fact, there's no such thing.

A herbal Viagra has never been approved as a treatment for erectile dysfunction.

Plus, these treatments may be fake or unsafe.

Can women use it?

Women can take sildenafil for pulmonary hypertension.

There's no good evidence that sildenafil works for women with sexual problems.

Will it affect my contraception?

Sildenafil does not affect any type of contraception, including the combined pill or emergency contraception.

Can I drive or ride a bike?

Sildenafil does not make you sleepy and so it's usually safe to drive or ride a bike while taking this medicine.

However, do not drive, cycle or operate machinery if it makes you feel dizzy or affects your eyesight.

Can I drink alcohol while taking sildenafil?

Yes, you can drink alcohol while taking sildenafil.

But drinking lots of alcohol can make it more difficult to get an erection. To get the most benefit from sildenafil if you're taking it for erection problems, do not drink much alcohol before taking it.

Is there any food or drink I need to avoid?

Do not drink grapefruit juice if you're taking sildenafil (Revatio) for pulmonary hypertension. It affects the way the medicine works.

You can eat and drink normally while taking sildenafil to get an erection.

Will recreational drugs affect it?

Taking poppers (amyl nitrite) with sildenafil can have a dangerous effect on your heart.

It can also be dangerous to take sildenafil with:

  • stimulants like MDMA (ecstasy) or cocaine
  • hallucinogens like LSD
  • novel psychoactive substances (which used to be known as legal highs) like mephedrone

Sildenafil has not been properly tested with recreational drugs.

Talk to your doctor if you think you might use any recreational drugs with sildenafil.

You can find out about the side effects of recreational drugs on the Frank website.

Can lifestyle changes help with erection problems?

Erection problems (erectile dysfunction) can often get better if you make changes to your lifestyle, such as:

  • maintaining a healthy weight
  • quitting smoking
  • cutting down on the amount of alcohol you drink
  • not taking recreational drugs
  • exercising
  • reducing stress

Page last reviewed: 2 March 2022
Next review due: 2 March 2025