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What does it do?

Tadalafil is used to treat impotence (difficulty getting and maintaining an erection) in men.

How should you take it?

Take tadalafil with a glass of water between half an hour and 36 hours before having sex, or as directed.

What if you forget a dose?

Take tadalafil when required. The maximum dose is one tablet a day.

Can you take other medicines?

Some medicines available without a prescription may react with tadalafil including:

  • glyceryl trinitrate (e.g. Nitrolingual Pumpspray®, Lycinate®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products (e.g. St John's wort) or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Prolonged erection (longer than four hours)

Changes in vision

Tell your doctor immediately

Headache, dizziness, hot flushing

Runny or blocked nose

Back pain, muscle aches and pains


Tell your doctor if troublesome

Stomach upset

Take with food

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • Tell your doctor if you have blood pressure, bleeding, blood, stomach, heart, liver, kidney, penis (other than impotence), hearing or eye problems; or if you have had a recent stroke.
  • Grapefruit, grapefruit juice or sour/Seville oranges may react with tadalafil. Discuss with your pharmacist.
  • If you are taking nitrate medicines (e.g. glyceryl trinitrate), you should not use tadalafil. Discuss with your doctor or pharmacist.

This leaflet contains important, but not all, information about this medicine.

Prepared by the PILs Committee at Christchurch Hospital, Canterbury District Health Board, New Zealand. December 2017

For more general information about this sheet annd its contents, see: What does a My Medicines sheet cover?

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About My Medicines

My Medicines Patient Information Leaflets (PILs) contain important, but not all, information about the medicines they describe.

For more information about the sheets, see: What does a My Medicines sheet cover?

My Medicines is developed by a team at the Canterbury District Health Board. Our team is made up of doctors, pharmacists, and a non-medical person to help us keep to plain language. We also discuss our information with specialist health professionals or groups when needed