Decongestant medication

Decongestants are a type of medicine that can provide short-term relief for a blocked nose (nasal congestion).

They can be taken to ease the symptoms of congestion when you have:

Many decongestants can be bought over the counter in pharmacies without a prescription. They are available as tablets or a nasal spray.

How decongestants work

The skin lining in your nose contains many tiny blood vessels. If something irritates this lining, such as an infection or allergy, more blood flows to these vessels as part of your body's immune response, making them swell.

This can block your nasal airway, making it difficult for you to breathe through your nose.

Decongestants reduce swelling of the blood vessels inside your nose. This helps to open up your nasal airway, making breathing easier.

However, although decongestants can help you to breathe more easily, they cannot cure the underlying cause of your blocked nose, such as a cold or allergy.

Things to consider when using decongestants

Decongestants are not usually recommended for children aged under 12, for women who are breastfeeding and for people with certain health conditions, such as high blood pressure.

Speak to your pharmacist or GP if you are unsure whether to take decongestants.

Read more about issues you need to consider before taking a decongestant.

It is not recommended to use decongestants for more than seven days, as they can cause your nose to become more blocked once you stop taking them (rebound congestion).

If your symptoms fail to improve after this time you should contact your GP.

Side effects

When side effects occur after taking decongestants, they tend to be mild. These can include:

  • dry mouth
  • headache
  • feeling sick

More serious side effects have been reported, such as hallucinations (seeing and hearing things that are not real) and a severe allergic reaction (anaphylaxis), but these are rare.

Read more about the side effects of decongestants.


It is now commonplace for decongestants to be sold as part of an "all-in-one" cold, flu or hay fever remedy, where the decongestant medication is also combined with painkillers, such as ibuprofenparacetamol or with antihistamines (used to treat allergies).

It is important to carefully read the patient information leaflet that comes with your medication, as it could be dangerous to take one of these "all-in-one" remedies and then go on to take extra ibuprofen, paracetamol or antihistamines.

You should not take decongestants if you are taking a type of antidepressant called a monoamine oxidase inhibitor, as this can cause a dangerous rise in blood pressure.

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