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Can I take Sildenafil and Grapefruit together?

Drug interaction guide

Drinking grapefruit juice or eating grapefruit while taking sildenafil can significantly increase the amount of the medicine in your bloodstream. This makes side effects much more likely and potentially more severe. You may experience a very fast or irregular heartbeat, headaches, dizziness, flushing, or a sudden drop in blood pressure which could lead to fainting.

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Why this happens

Your body uses a specific enzyme (called CYP3A4) in the gut and liver to break down sildenafil. Grapefruit contains natural compounds that 'block' this enzyme. Because the enzyme is busy dealing with the grapefruit, it cannot break down the sildenafil as quickly as usual, leading to higher-than-intended levels of the drug in your body.

What you should do

It is best to avoid grapefruit and grapefruit juice entirely while using sildenafil. If you have already consumed grapefruit, wait at least 24 hours before taking a dose of sildenafil. If you experience chest pain, dizziness, or a prolonged erection (lasting more than 4 hours) after taking this combination, seek medical help immediately.

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Important precautions

Nitrate medication use (e.g. GTN spray, isosorbide mononitrate)

You must never take sildenafil if you are using nitrate medicines for chest pain or heart problems. Combining them can cause a sudden, life-threatening drop in blood pressure.

Grapefruit consumption

Avoid eating grapefruit or drinking grapefruit juice while using sildenafil. Grapefruit increases the amount of the medicine in your blood, which significantly raises the risk of dangerous side effects.

Food and drink warnings

Grapefruit and grapefruit juice

Grapefruit juice can increase the amount of sildenafil in your blood. This may increase the risk of side effects like headaches, flushing, or low blood pressure. It is best to avoid drinking large amounts of grapefruit juice while taking this medicine.

Alcohol

Drinking alcohol can make it harder to get an erection. Alcohol can also lower your blood pressure; taking it with sildenafil may cause your blood pressure to drop too low, leading to dizziness or fainting. It is recommended to keep alcohol intake to a minimum.

High-fat meals

If you take sildenafil with a heavy or high-fat meal (such as a burger and chips), the medicine may take longer to start working. For the fastest effect, it is best taken on an empty stomach or with a light meal.

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Using other medicines

Taking multiple medicines? Our Medicines Interaction Checker helps you check whether your prescriptions, over-the-counter medicines, and supplements are safe to take together. Simply search for your medicines to see potential interactions and what to do about them.

Disclaimer

This information is for general educational purposes only and should not be relied upon as a substitute for professional medical advice. Always consult your GP, pharmacist, or another qualified healthcare professional before making decisions about your medications. Individual circumstances may vary, and only a healthcare professional who knows your medical history can provide personalised guidance.

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Article history

The information on this page is written and peer reviewed by qualified clinicians.

  • 24 Jan 2026 | Originally published
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