Skip to main content
Pharmacy Online - Home

Jext 0.3mg Pen

Jext 0.3mg Pen

Images for illustrative purposes only

Prescription Range

Jext 0.3mcg pen is a pre-filled adrenaline auto injector emergency treatment for severe allergic reactions or anaphylaxis. It contains adrenaline and is designed to be administered into the outer thigh muscle in an allergic emergency. It works by preventing blood pressure from dropping dangerously low.

  • Adrenaline auto injector for emergency use when experiencing anaphylactic reaction
  • For fast treatment of anaphylaxis and severe allergic reactions
Anaphylaxis
General Health
Price
£73.99

Jext 0.3mg Pen

Pack Size: 1 x Jext Pen

£73.99

Looking for Next Day delivery?

Order before 15:30 for next day delivery on working days

Buy Jext 0.3mg Pen Online

Jext 0.3mg pen is a prescription-only, pre-filled adrenaline auto injector used to treat anaphylaxis in a medical emergency.

Buy Jext injection pen online from our secure online pharmacy service after a short consultation with one of our doctors or pharmacists.

When to Use the Jext 0.3mg Pen?

The Jext 0.3mg pen is an adrenaline auto-injector offering emergency treatment for acute allergic reactions brought on by allergens, including foods, bites, and stings.

If you have an allergy and are suffering from any of the following, you should use the pen immediately:

  • Breathing Issues: Coughing, problems swallowing, wheezing, and a tight throat.
  • Circulation Issues: Other signs of an allergic reaction include suddenly feeling tired, dizzy, faint or losing consciousness, and clammy skin.
  • Swelling: Swelling of the throat and tongue also requires instant attention.
  • Skin Symptoms: Itching and skin rashes - including hives - are common signs of allergic reactions.

Even if you're unsure of whether the reaction will likely be severe, you should still use the adrenaline injection immediately, as a minor reaction can quickly become life-threatening.

Jext 0.3mg Pen Age Restrictions

The Jext injector doesn't have specific age restrictions. Instead, it's only recommended for adults and children over 30kg (4.7 stone).

Please don't administer the pen to anyone who doesn't meet these requirements, unless it's the only available option. You'll also need to reduce the dosage.

How to Use the Jext Adrenaline Pen?

While the Jext pen is simple to use, following the instructions carefully is essential. These include:

  1. Site Preparation: Hold the Jext pen around the middle and ensure your thumb is close to the yellow cap. Use your other hand to pull off the yellow cap, which prepares the injection.
  2. Inject: Hold the black injector tip to the thigh's outer side, at a right angle. These injections can go through most types of clothing, but avoid administering them near thick seams, zippers, and buttons. Push down the black tip until you hear a clicking sound, and count for 10 seconds.
  3. Post-Injection: After removing the injector, check the window to ensure a coloured rod is visible. This means that the adrenaline was successfully injected. Then, massage the injection site for 10 seconds to ensure absorption.

Please note that it's best to immobilise a child's legs when administering adrenaline to ensure they receive the full dose.

When to Avoid Using Jext 0.3mg Pen?

As a potentially life-saving treatment, the Jext pen is suitable for anyone with allergies during a severe reaction (analyphalatic shock).

However, it shouldn't be administered to individuals who don't have allergies or people under 30kg - unless it's an emergency situation.

If any of the following apply, you should avoid using the pen:

  • Past Expiry Date: Adrenaline will degrade over time. In absolute emergencies, where you only have an expired pen, you should still use it.
  • Discoloured Solutions: Check the inspection window before removing the cap. If it's cloudy or discoloured, discard that pen and use another one.

Precautions for Jext 0.3mg Pen

Please take care when using the pen, as injecting it into the wrong site can result in complications.

The most important places to avoid include the buttocks and the lower extremities, which can compromise blood flow.

Accidentally injecting the pen into a vein is highly unlikely, but seek instant medical care if you do, as it can cause a heart attack.

Ingredients of Jext 0.3mg Pen

Adrenaline (Epinephrine) is the active ingredient in the Jext Pen, but it also has inactive ingredients, including:

  • Sodium Metabisulphite
  • Water
  • Hydrochloric Acid
  • Sodium Chloride

Side Effects of Jext 0.3mg Pen

Like all medicines, Jext auto injector can have side effects.

Side effects of adrenaline can include heart problems like a rapid heartbeat and chest pain, sweating, nausea, vomiting, anxiety and tremors, and difficulty breathing.

However, the side effects of adrenaline outweigh the risk of not administering it.

What is Jext?

Jext is a brand of adrenaline (epinephrine) auto-injectors. It’s a device that contains adrenaline and is designed to be easy to inject in emergencies. It’s used to treat severe allergic reactions (anaphylaxis).

It should be used as soon as you suspect a severe allergic reaction. It can be self-administered or administered by someone else who is helping you.

What are severe allergic reactions (Anaphylaxis)?

Anaphylaxis, or anaphylactic shock, is a severe and potentially life-threatening reaction to a trigger like an allergy. It happens when the body's immune system overreacts to a trigger.

This overreaction can cause various symptoms such as swelling of the throat, lips and tongue, rash, breathing difficulties, shortness of breath and trouble breathing, vomiting, and nausea.

It can also lead to serious problems with the cardiovascular system and blood flow

Anaphylaxis is a medical emergency, and you should always call 999 for help, even if you have used an adrenaline auto-injector to treat it.

How does Jext work?

Jext pens work by delivering adrenaline into the body with an injection. Each adrenaline pen contains a single adult dose of adrenaline.

The Jext injections work on the respiratory and cardiovascular systems to stop anaphylaxis's serious effects. It causes blood vessels to constrict, stimulates the heartbeat, relaxes muscles in the lungs to improve breathing, and reduces swelling.

What is the Jext dosage?

The recommended dose for adults and children who weigh over 30kg is Jext 300 micrograms injected into the outer thigh muscle for allergic emergencies.

It’s recommended that children who weigh between 15kg and 30kg use Jext 150mcg for allergic emergencies. At Pharmacy Online, we only offer the 300mcg strength for adults over 18 years old.

If you’re unsure about the correct dose, speak to your GP for advice.

Sometimes a single dose of adrenaline may not be sufficient to completely reverse the effects of a serious allergic reaction. This is why you should always carry two adrenaline pens.

If symptoms have not improved within 5 - 15 minutes of the first injection, you should use a second injection.

How long does Jext take to work?

Jext will typically start to work immediately, reducing symptoms of anaphylaxis. If symptoms persist, you may need to immediately administer a second injection.

You should always call for emergency assistance when you experience a severe allergic reaction or anaphylactic episode, even if you have successfully administered adrenaline.

Where can I buy a Jext 0.3mcg pen?

You can buy Jext adrenaline auto-injectors from our UK-registered online pharmacy and doctor service. As part of your order, simply complete an online assessment for our prescribers to review.

This service is only available to patients who have previously been prescribed this medicine by their GP.

What should I do in the event of an accidental injection?

If you accidentally inject Jext, immediately seek medical attention. Accidents often occur when someone accidentally presses the injector into their thumb or finger, and not seeking urgent medical care can cause a range of complications.

Leaflets

Jext 0.3mg Pen Patient Information Leaflet

Please read the Jext Patient Information Leaflet carefully before using the pen. If you're unsure how to use the auto injector or have any questions, please contact our registered pharmacists for advice.

Jext Patient Information Leaflet

Umar Razzaq, MPharm | University of Strathclyde, Clinical Pharmacist.
Content Written by:Umar RazzaqMPharm | University Of Strathclyde
Date Written:01/03/2024
Role:Clinical Pharmacist
Nish Fayyaz, MPharm | University of Strathclyde, Pharmacist.
Medically Reviewed By:Nish FayyazMPharm | University Of Strathclyde
Date Checked:30/05/2025
Role:Pharmacist
Fully inspected and regulated service
UK registered pharmacy
Approved UK-licensed treatments
Discreet next day delivery