Allergies: When to Use Your Auto-Injector

Medically Reviewed by Carol DerSarkissian, MD on February 05, 2022

One big reason auto-injectors are so important for people with allergies: You can't predict allergic reactions. They can be mild one time and serious the next. An attack can quickly become intense and sometimes lead to anaphylaxis -- a severe, often life-threatening reaction.

An auto-injector, such as an Adrenaclick, Auvi-QEpiPen, Symjepi or a generic version, can treat it with a dose of epinephrine. It can help improve your breathing, raise your blood pressure if it's dropping, and reduce swelling.

When you have an allergic reaction, you may wonder if it's time to give yourself a shot with an auto-injector. Experts say even if there's any doubt, use it. It's much more dangerous not to get epinephrine when you're having a severe reaction than to get a dose you don't really need.

Keep the Injector Handy and Ready

The device won't do you any good if you don't have it with you. When you pick up your prescription at the drugstore, you'll get two injectors. Carry both with you at all times in case one doesn't work or you have a reaction and need a second dose.

Extreme heat and cold can damage the medication in your auto-injectors, so store them at room temperature. Don't leave them in your car.

The injectors are usually good for a year, so keep track of the date on the box.

When to Take the Shot

There are many cases when you, or someone you know, need to use an auto-injector, but two general ones are:

  • You have a life-threatening allergy and you know you've had contact with your allergy trigger. An example: If you have a peanut allergy and your boyfriend ate some peanuts and then kissed you, don't wait for symptoms -- take the epinephrine right away.
  • You have allergy symptoms -- even if you don't know the trigger.

Those symptoms can include:

What to Do After a Shot

Take these steps after the first injection:

  • If there's no relief, take a second dose. You could wait as few as 5 minutes for a severe reaction or 15 minutes if it is mild.
  • Have someone call 911.
  • Massage the injection site for 10 seconds to stimulate blood vessels and help the body absorb the medication.
  • Go to the emergency room after an injection, even if your symptoms get better or seem to go away. Severe episodes can last 4 to 12 hours, and you never know at the beginning how long yours will last.

Create a Plan

The common side effects from the epinephrine injection are dizziness, restlessness, anxiety, and shakiness. In rare cases, they may be more severe.

Work with your doctor to make a plan that's just for you. It should outline when you need to have an injection and how to recognize signs of a severe allergic reaction.

Share the plan with anyone who might have to use the injector on you, like your spouse or co-workers. If your child carries an auto-injector, give the plan to their teachers, school nurse, babysitter, and grandparents.

Practice using the device. Check online for safety videos and updates. And make sure anyone who may have to use it knows how.

Show Sources


Jane Purser, MD, Allergy Clinic of Tulsa, OK.

Rabia Chaudhry, MD, Allergy, Asthma and Immunology Management, Moorestown, NJ.

American College of Allergy, Asthma & Immunology: “When to Use an Epinephrine Auto-injector.”

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