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EpiPen Auto-Injector

Generic name: epinephrine injectionEP-i-NEF-rin ]
Brand names: EpiPen 2-Pak, EpiPen JR 2-Pak
Drug classes: Adrenergic bronchodilators, Catecholamines, Vasopressors

Medically reviewed by Philip Thornton, DipPharm. Last updated on Oct 10, 2021.

What is EpiPen?

EpiPen is an injection containing epinephrine, a chemical that narrows blood vessels and opens airways in the lungs. These effects can reverse severe low blood pressure, wheezing, severe skin itching, hives, and other symptoms of an allergic reaction.

EpiPen Auto-Injectors are used to treat severe allergic reactions (anaphylaxis) to insect stings or bites, foods, drugs, and other allergens.

EpiPen is also used to treat exercise-induced anaphylaxis.

EpiPen Auto-Injectors may be kept on hand for self-injection by a person with a history of severe allergic reaction.

An Auto-Injector is a hand-held device that automatically injects a measured dose of medicine.


EpiPen Auto-Injectors are used to treat severe allergic reactions (anaphylaxis).

Seek emergency medical attention even after you use EpiPen to treat a severe allergic reaction. The effects may wear off after 10 or 20 minutes. You will need to receive further treatment and observation.

Before using EpiPen a second time, tell your doctor if your first injection caused a serious side effect such as increased breathing difficulty, or dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, shortness of breath, uneven heartbeats, seizure).

The EpiPen Auto-Injector (0.3 mg) is for patients who weigh 66 pounds or more (30 kilograms or more).

The EpiPen Jr Auto-Injector (0.15 mg) is for patients who weigh about 33 to 66 pounds (15 to 30 kilograms).

It is not known if EpiPen is safe and effective in children who weigh less than 33 pounds (15 kilograms).

Before using this medicine

Before using EpiPen, tell your doctor if any past use has caused an allergic reaction to get worse.

To make sure this medicine is safe for you, tell your doctor if you have ever had:

Having an allergic reaction while pregnant or nursing could harm both mother and baby. You may need to use EpiPen during pregnancy or while you are breastfeeding. Seek emergency medical attention right away after using the injection.

If possible during an emergency, tell your medical caregivers if you are pregnant or breastfeeding.

How should I use EpiPen?

The EpiPen Auto-Injector device is a disposable single-use system. Use an Auto-Injector only one time.

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you do not understand these instructions.

Do not remove the safety cap until you are ready to use the Auto-Injector. Never put your fingers over the injector tip after the safety cap has been removed.

Do not give this medicine to a child without medical advice.

EpiPen is injected into the skin or muscle of your outer thigh. In an emergency, this injection can be given through your clothing.

To use an EpiPen Auto-Injector:

  • Form a fist around the Auto-Injector with the black tip pointing down. Pull off the safety cap.

  • Place the black tip against the fleshy portion of the outer thigh. You may give the injection directly through your clothing. Do not put your thumb over the end of the unit. Hold the leg firmly when giving this injection to a child or infant.

  • With a quick motion, push the Auto-Injector firmly against the thigh. This will release the spring-loaded needle that injects the dose of epinephrine. Hold the Auto-Injector in place for a few seconds after activation.

  • Remove the Auto-Injector from the thigh. Carefully re-insert the used device needle-first into the carrying tube. Re-cap the tube and take it with you to the emergency room so that anyone who treats you will know how much epinephrine you have received.

Also seek emergency medical attention if you accidentally inject yourself while giving EpiPen to another person.

Accidentally injecting EpiPen into your hands or feet may result in a loss of blood flow to those areas, and resulting numbness.

Use an Auto-Injector only once, then throw away in a puncture-proof container (ask your pharmacist where you can get one and how to dispose of it). Keep this container out of the reach of children and pets.

Do not try to reuse the same Auto-Injector a second time. If the needle is bent from the first use, it may cause serious injury to your skin.

Do not use the EpiPen if it has changed colors or has any particles in it, or if the expiration date on the label has passed. Call your doctor for a new prescription.

Your medicine may also come with a "trainer pen." The trainer pen contains no medicine and no needle. It is only for non-emergency use to practice giving yourself an injection.

Store at room temperature away from moisture, heat, and light. Do not refrigerate this medication, and do not store it in a car.

What happens if I miss a dose?

Since EpiPen is used when needed, it does not have a daily dosing schedule.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include numbness or weakness, severe headache, blurred vision, pounding in your neck or ears, sweating, chills, chest pain, fast or slow heartbeats, severe shortness of breath, or cough with foamy mucus.

What should I avoid while using EpiPen?

Do not inject EpiPen into a vein or into the muscles of your buttocks, or it may not work as well. Inject it only into the fleshy outer portion of the thigh.

EpiPen side effects

Before using EpiPen, tell your doctor if any past use has caused an allergic reaction to get worse.

Call your doctor at once if you notice pain, swelling, warmth, redness, or other signs of infection around the area where you gave an injection.

Side effects may be more likely in older adults.

Common EpiPen side effects may include:

  • breathing problems;

  • fast, irregular, or pounding heartbeats;

  • pale skin, sweating;

  • nausea and vomiting;

  • dizziness;

  • weakness or tremors;

  • headache; or

  • feeling restless, fearful, nervous, anxious, or excited.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect EpiPen?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with epinephrine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Where can I get more information?

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use EpiPen only for the indication prescribed.

Popular FAQ

Epipen (epinephrine injection) is given as an intramuscular (in the muscle) or subcutaneous (under the skin) injection only in the middle of the outer side of the thigh (the upper leg). It can be injected through clothing if needed. Continue reading

EpiPen and Symjepi are both for intramuscular or subcutaneous use to treat allergic emergencies (anaphylaxis). Unlike EpiPen, Symjepi does not come as an "autoinjector" but comes only as a prefilled syringe. Symjepi has smaller size and may be more user-friendly than other products. Continue reading

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Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.