Nasal decongestants

Decongestants are used to help unblock a stuffy or blocked nose. Find out how to take it safely and possible side effects.

Decongestants help to unblock a stuffy or blocked nose. They work by narrowing blood vessels in your nose, throat and sinuses. Decongestants are available as nasal sprays or as tablets or capsules. Decongestant nasal sprays clear a blocked nose immediately. Tablets or capsules may take a little longer to work because they need to be absorbed into your body from your digestive system (guts).

On this page, you can find the following information:

Tablets and capsules

Examples of decongestants found in cold and flu tablets and capsules are phenylephrine. Decongestant tablets and capsules can cause increased blood pressure and heart rate, anxiety, restlessness and sleep problems (insomnia).

Nasal decongestants

Nasal decongestants are used for the short-term relief of stuffiness or congestion of the nostrils that may be caused by the common cold, sinusitis, allergies or hay fever. Nasal decongestants are available as a nose spray or nose drops. They clear a blocked nose immediately.

Some nasal decongestants such as oxymetazoline (Drixine®) and xylometazoline (Otrivin®) work by narrowing blood vessels in the nose, throat and sinuses. They are only for short term use (usually only for 3 days- check the product packaging). If you use them for longer than this, a rebound more severe congestion of your nose can happen.

Other examples of nasal sprays that can ease congestion are:

  • saline nasal sprays or drops which may help to thin the mucous and may reduce the amount of secretions from your nose
  • ipratropium nasal spray which helps to relieve a runny nose by drying up secretions of your nose and helps to stop mucous glands in your nose from overproducing watery mucous. Note: ipratropium can cause nasal dryness and nose bleeds.

Who can't take decongestants?

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

  • problems with your heart or kidneys
  • high blood pressure (hypertension)
  • diabetes
  • glaucoma
  • problems with your thyroid gland
  • prostate problems.


Intranasal decongestants (containing oxymetazoline and xylometazoline) should not be used in children aged less than two years old. Other medicines for coughs and colds should not be used in children aged less than six years old.

How to use nasal drops

Use the nasal drops as follows:

  • Gently blow your nose with a tissue to clear the nostrils.
  • Tilt your head back while sitting on a chair or lying down.
  • Hold the dropper over one nostril and squeeze in the required number of drops.
  • Keep your head tilted for a few seconds.
  • Repeat the steps for the other nostril.
  • Wipe the dropper with a clean tissue after each use.

How to use a nasal spray

Use the nasal spray as follows:

  • Shake the nasal spray before use.
  • Gently blow your nose with a tissue to clear the nostrils.
  • Use your finger to close the nostril on the side not receiving the medication.
  • Place the spray tip into the open nostril.
  • Spray the medication into the open nostril as you breathe in through your nose.
  • Sniff a few times to be sure the medication reaches deep into your nose.
  • Repeat the steps for the other nostril.
  • Wipe the spray tip with a clean tissue and put the cap back on.

What are the side effects of decongestants (nasal)?

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 troublesome.
  • Dizziness
  • Headache
  • Shaking tremors
  • Trouble sleeping 
  • Tell your doctor if troublesome.
  • Signs of rebound nasal congestion, such as 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 side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product

Learn more

How to use nasal sprays properly Safe Medication, American Society of Health-System Pharmacists


  1. Systemic nasal decongestants New Zealand Formulary
  2. Topical nasal decongestants New Zealand Formulary
  3. Cold season: managing without antibiotics BPAC, NZ, 2018
  4. Cold season in primary care BPAC, NZ, 2013
Credits: Sandra Ponen, Pharmacist. Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 02 Jul 2018