This website has been developed and funded by ALK and is intended for patients who have been prescribed Jext ®, their parents and carers.

When to
use Jext®

Anaphylaxis can develop rapidly within minutes, or over a period of hours.

When you come into contact with an allergen, Jext® should be given immediately if any of the below symptoms occur.


Only a few of the following symptoms may be present, however some can be LIFE-THREATENING.

  • Itching of the skin
  • Raised rash (like a nettle rash)
  • Flushing
  • Swelling of the lips, throat, tongue, hands and feet
  • Wheezing, hoarseness, shortness of breath
  • Nausea, vomiting and stomach cramps
  • Vomiting, diarrhoea, cramps
  • In some cases, loss of consciousness


If you experience any or all of these symptoms, it is time to use Jext® and call 999 in the UK, or 112 in Ireland, ask for an ambulance and say ‘anaphylaxis’. Always use your medicine as you were instructed by your doctor. It is important to remember that the pattern of symptoms you experience may be different from previous reactions.


Jext® is designed for you to use quickly and confidently in an emergency, to treat a severe allergic reaction and give you time to get to a hospital.

Emergency Shot

Jext® app

Download the free Jext® app, available for iPhone and Android, for:

  • Information on anaphylaxis
  • Instructions for using Jext®
  • Demonstration videos
  • An expiry alert reminder system
Download app now