What Is Epinephrine? Uses, Dosage, and What You Need to Know in 2026

Epinephrine is one of the most important emergency medications in existence. It is the drug of choice for treating anaphylaxis — the severe, life-threatening allergic reaction that can kill within minutes. This guide covers everything you need to know about epinephrine: what it is, what it treats, how it's dosed, and what to do in an emergency.

What Is Epinephrine?

Epinephrine — also known as adrenaline — is a naturally occurring hormone and neurotransmitter produced by the adrenal glands. It plays a central role in the body's 'fight or flight' response, rapidly preparing the body to handle stress or danger. As a medication, epinephrine is a sympathomimetic catecholamine that acts on both alpha and beta adrenergic receptors throughout the body.

Brand names include EpiPen, EpiPen Jr, Auvi-Q, Adrenaclick, Adrenalin, and Symjepi. A nasal spray form called neffy was FDA-approved in August 2024. The generic name is epinephrine, and it is not a controlled substance.

What Is Epinephrine Used For?

The primary use of epinephrine auto-injectors is emergency treatment of anaphylaxis. It is FDA-approved for:

Anaphylaxis caused by insect stings or bites (bees, wasps, hornets, fire ants)

Anaphylaxis caused by foods (peanuts, tree nuts, shellfish, dairy, eggs, wheat, and others)

Anaphylaxis caused by drugs, vaccines, radiocontrast media, or other allergens

Idiopathic anaphylaxis (anaphylaxis of unknown cause)

Exercise-induced anaphylaxis

Epinephrine is also used in hospital settings in IV or subcutaneous form for: septic shock (low blood pressure), cardiac arrest (as part of ACLS protocols), severe asthma not responding to bronchodilators, croup, and as a vasoconstrictor added to local anesthetics to prolong their effect.

Epinephrine Dosage: How Much and When?

For auto-injectors used in anaphylaxis, dosing is based on patient weight:

Less than 7.5 kg: Auto-injectors are not indicated; use manual epinephrine with appropriate weight-based dosing

7.5 kg to less than 15 kg: Auvi-Q 0.1 mg (only auto-injector approved for this weight range)

15 kg to less than 30 kg: EpiPen Jr 0.15 mg, Auvi-Q 0.15 mg, or Adrenaclick 0.15 mg

30 kg or more: EpiPen 0.3 mg, Auvi-Q 0.3 mg, Adrenaclick 0.3 mg, or Symjepi 0.3 mg

The injection is given intramuscularly into the anterolateral aspect of the thigh (the outer middle portion) — this can be through clothing. The injection may be repeated every 5–15 minutes if symptoms don't improve, but more than two sequential doses should only be administered under direct medical supervision.

How to Use an Epinephrine Auto-Injector

General steps for using an EpiPen (always practice with the trainer device first, as specific steps vary by device):

Remove from storage case. Check that the solution in the viewing window is clear and colorless.

Remove safety cap (blue cap on EpiPen — 'blue to the sky, orange to the thigh').

Place the orange tip firmly against the outer middle thigh, can be through clothing.

Press firmly until you hear a click. Hold for approximately 3 seconds.

Remove the auto-injector. Massage the injection site for 10 seconds.

Call 911 immediately. Lie down with legs elevated if possible (unless this worsens breathing).

Storage Requirements: What You Need to Know

Proper storage is critical because epinephrine degrades if not stored correctly:

Temperature: Store at 68°F–77°F (20°C–25°C). Excursions to 59°F–86°F (15°C–30°C) are permitted briefly.

Do not refrigerate: Refrigeration can damage the device mechanism.

Protect from light: Keep in the carrier tube. Epinephrine turns pink (from oxidation) then brown when exposed to light or air — if the solution is discolored, replace it.

Check expiration dates: Replace before expiration. Auto-injectors typically have a 12–18 month shelf life from dispensing.

Key Reminders for Patients

Always carry two auto-injectors — a second dose may be needed in 16–35% of anaphylaxis cases

Practice with the trainer device before you need the real one in an emergency

Always go to the emergency room after any epinephrine use — biphasic reactions can occur hours later

Keep epinephrine sets at school, work, and home if you have severe allergies

Never inject into the buttocks or a vein — only the outer middle thigh

To understand how epinephrine produces these effects, read our post on how epinephrine works.