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


What is Jext®?

Jext® is a single-use adrenaline auto-injector. Each Jext® injects a premeasured single dose of adrenaline for the emergency treatment of anaphylaxis. The needle is contained within the Jext® before use and is automatically covered by the black tip after use.

How does adrenaline work?

Adrenaline should be injected into the muscle of the upper outer thigh for the emergency treatment of anaphylaxis because it works quickly to reverse the symptoms of an anaphylactic reaction.

Adrenaline acts to raise low blood pressure which can cause dizziness, collapse and loss of consciousness in anaphylaxis. It also relaxes smooth muscle in the lungs to improve breathing and reduces swelling around the face and lips.

Why is Jext® available in different doses?

The appropriate dose will be decided by your doctor, who will adjust it individually for you.

Adults and Children over 30kg – the usual dose for self-administered adrenaline in allergic emergencies is 300 micrograms of adrenaline for injection into the outer thigh muscle.

Children between 15kg and 30kg – the usual dose for self-administered adrenaline in allergic emergencies is 150 micrograms of adrenaline for injection into the outer thigh muscle.

Remember: the correct dose of Jext® depends on bodyweight.

Does Jext® contain Latex?

Jext® is Latex free.

There is an 'air' bubble in my Jext® is it still OK to use?

The bubble is perfectly normal to find in Jext®. You can confidently use your Jext® as the bubble will not affect either the medication or the mechanism.

What should I do if the liquid visible through the inspection window is no longer clear and colourless?

Contact your doctor to arrange to replace your Jext® if the adrenaline solution visible through the inspection window becomes discoloured or contains particles.

How should I use Jext®?

Always use Jext® exactly as your doctor has told you. Make sure you understand in what situations you should use Jext®. If you are at all unsure about how to use it, ask to have the instructions repeated by your doctor, nurse or pharmacist.

Jext® should be pushed firmly against the outer portion of the thigh into the largest part of the thigh muscle. When you push Jext® firmly against your thigh, a spring activated plunger will be released, which pushes the hidden needle through the seal at the end of the black needle shield, into the thigh muscle and injects a dose of adrenaline.

Before you ever need to use it, you should familiarise yourself with Jext® and practise using a Jext® Trainer together with the training video.

How will I know that my Jext® has worked and that I have received my medicine?

When the Jext® activates to deliver the medicine a distinct ‘click’ will be heard. The inspection window in the label will be filled by a white or blue coloured plastic rod to confirm that adrenaline has been injected and a needle guard will extend to cover the needle.

Can Jext® be used through clothing?

Yes, Jext® is specifically designed to reliably operate through clothing, including tough fabrics such as denim.

After using Jext® what should I do?

Jext® should be considered first aid and you should always seek medical attention after using it. After administering Jext®, call 999 in the UK, or 112 in Ireland, ask for an ambulance and say ‘anaphylaxis’ – or get someone else to do so. Pass the used Jext® to a Healthcare Professional when you seek medical assistance. Remember to get a replacement.

How do I use my Jext® Trainer?

Your Jext® Trainer works in exactly the same way as a real Jext® although there is no adrenaline and no needle in the Trainer. The Jext® Trainer has a grey label to differentiate it from the real Jext® device.

Unlike a real Jext®, the Trainer can be reset and used as many times as you need to become familiar with the correct technique.

You, your family and friends should use the Jext® Trainer together with the demonstration video to ensure you are fully prepared and confident if you need to use your Jext® in the future.

How can I obtain a Jext® Trainer?

You can order a Jext® Trainer by clicking here.

What should I tell family, friends and colleagues?

Make sure that you tell family, friends and colleagues what to do if you were to experience anaphylaxis. They should know how to recognise the symptoms and how to administer your Jext® if required.

A Jext® Trainer and Action Plan may be of assistance in teaching others who may be available to help if you experience anaphylaxis. Ask them to visit this website to learn more.

How should I store my Jext®?

Jext® should be stored within the flip-top case provided. Store below 25°C. Do not freeze.

How can I remember to replace my Jext® when it is due to expire?

Automatic expiry alerts can be set up by clicking here and registering online.

I have noticed that my Jext® is due to expire, what do I do?

Contact your doctor to arrange to replace your Jext® by the expiry date stated on the label and printed on the box. The expiry date refers to the last day of the month.

Automatic expiry alerts can be set up here.

How do I dispose of an out-of-date Jext® which has not been used?

You should contact your GP surgery or your Local Authority who will be able to advise you of the local arrangements for disposal of an out of date Jext®.

Are there any precautions I should take with my Jext® when I go on holiday?

Make sure that you have sufficient Jext® auto-injectors with you.

Check with your holiday company or airline whether a letter from your GP will be required permitting you to carry your Jext® onboard the aircraft. You can create your travel certificate by clicking here.

When travelling abroad it is important you take the same level of care as you would at home. Prepare yourself by looking at our travelling abroad resources.

I am travelling to a very different climate to the UK and I wondered if my Jext® would still work properly?

When travelling you should take the same care of your Jext® as you would in the UK. Store your Jext® within the flip-top case. Store below 25°C. Do not freeze.