Mannitol challenge

What is a mannitol challenge test?

Mannitol is a naturally occurring sugar. A “mannitol challenge” test is a test that involves inhaling a fine mannitol powder, via an inhaler and assessing the response with a breathing test.

Why do I need to have this test?

The test has been requested to see if you have sensitivity of the airways in your lungs.

What happens during the test?

You will be asked to breathe in different concentrations of mannitol powder, via an inhaler. The concentration of the powder is gradually increased to assess the effect it has on your lungs. After each inhalation you will be asked to perform a simple breathing test, which you have probably done before. 

The whole test will last for approximately one hour.

Will I experience any discomfort or side effects?

Sometimes the test can cause a mild spasm of the airways, which may make you cough or short of breath. This is easily reversed by a common medication (salbutamol) that can be given if required at the end of the test. The powder may make your throat slightly dry which will be relieved with a drink of water.

Important information

It is important that you follow the instructions below carefully. You will not be able to do the test if you don’t.

  • Please stop taking all of your inhalers and asthma/ allergy medications (including antihistamines and montelukast) 4 days prior to this test. If required you can take salbutamol (Ventolin) and Bricanyl up to 8 hours prior to the test.
  • Please do not smoke for 6 hours prior to your appointment.
  • Please avoid foods and drinks that contain caffeine (tea, coffee, chocolate, cola and energy drinks) on the day of your appointment. You can continue to drink all other fluids.
  • Please avoid vigorous exercise on the day of your appointment.
  • Please inform us if you are pregnant or currently breast-feeding.

If you are unsure about whether you need to stop your medications or have any other questions about this test please contact us using the phone number on the back of this leaflet. 

Thank you for your cooperation. This will help us to obtain accurate information about your lungs and enable us to provide you with the most appropriate treatment.


Brannan, J.D., Anderson S.D., Perry C.P., Freed-Martens R., Lassig A.R. (2005) The safety and efficacy of inhaled dry powder mannitol as a bronchial provocation test for airway hyperresponsiveness: a phase 3 comparison study with hypertonic saline. Respir Res. 6:14

© North Bristol NHS Trust. This edition published June 2024. Review due June 2027. NBT002297.

Mannitol challenge