Key points about decongestants

  • Decongestants are used for the temporary relief of a stuffy or blocked nose or sinus congestion.
  • Decongestants are available as nasal sprays or as tablets or capsules.
  • Find out how to take them safely and possible side effects.
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Decongestants help to unblock a stuffy or blocked nose or congested sinuses. They work by narrowing blood vessels in your nose, throat and sinuses. Decongestants are available as nasal sprays and drops or as tablets and capsules.

Nasal decongestants (nasal sprays or drops)

Nasal decongestants are sprayed or dropped into your nose. They're used for the short-term relief of stuffiness or congestion of your nostrils that may be caused by the common cold, sinusitis, allergies or hay fever. Common examples of nasal decongestants include oxymetazoline (Drixine®) and xylometazoline (Otrivin®).

  • Nasal decongestants clear a blocked nose almost immediately.
  • They must be used for a short time only, usually only for 3 days (check the product packaging). If you use them for longer, they can cause rebound congestion of your nose and a painful or bleeding nose.

NOTE: Other examples of nasal products that can ease congestion are saline nasal sprays or drops and ipratropium nasal spray. Read more about how to use nose drops and sprays

Decongestant tablets and capsules

Phenylephrine is the decongestant commonly found in tablets and capsules.

  • It may be used alone or in combination with other ingredients in cold, flu, cough or sinus relief medicines.
  • Decongestant tablets and capsules can cause increased blood pressure and heart rate, anxiety, restlessness and sleep problems (insomnia). They are best used for a short time (a few days). Using them for longer than this could cause side effects.
  • Examples of decongestant tablets and capsules include Codral Decongestant, Codral Day & Night, Maxiclear Sinus Relief, Sudafed PE, Maxiclear Cold and Nasal Relief, Maxiclear Hayfever and Sinus Relief, Dimetapp Cold and Allergy, and Lemsip Max Cold & Flu.

Decongestants are not suitable for everyone. You should ask your doctor or pharmacist for advice if you have:


Intranasal decongestants (containing oxymetazoline and xylometazoline) shouldn't be used for children aged less than 2 years of age. Other medicines for coughs and colds should not be used for children aged less than 6 years of age.

Like all medicines, nasal decongestants can cause side effects, although not everyone gets them.

Side effects What should I do?
  • Burning, and stinging of your nostrils
  • Sneezing
  • These are quite common when you first use a nasal spray or nasal drops.
  • Tell your doctor if this bothers you.
  • Dizziness
  • Headache
  • Shaking tremors
  • Trouble sleeping 
  • Tell your doctor if they bother you.
  • Signs of rebound nasal congestion, eg, painful nostrils, increased or worsening runny nose, redness in your nostrils or bleeding nose.
  • Stop using the spray or drops.
  • Tell your doctor immediately.
Did you know that you can report a medicine side effect to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product(external link).

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

Last reviewed: