epinephrine

noun

epi·​neph·​rine ˌe-pə-ˈne-frən 

variants or less commonly epinephrin

: a crystalline sympathomimetic hormone C₉H₁₃NO₃ that is the principal blood-pressure raising hormone secreted by the medulla of the adrenal glands, is prepared from adrenal extracts or made synthetically, and is used medicinally especially to stimulate the heart during cardiac arrest and to treat life-threatening allergic reactions

called also adrenaline

Examples of epinephrine in a Sentence

Recent Examples on the Web

For an epinephrine injection to work, it should be given at the first sign of an allergic reaction. —Adrianna Rodriguez, USA Today, 12 June 2025

Here's What to Avoid What L-tyrosine Supplements Are Used For L-tyrosine is a component of important neurotransmitters like dopamine, norepinephrine, and epinephrine. —Sean Mowbray, Discover Magazine, 22 Apr. 2025

While people, particularly those with allergies, can take precautions such as carrying an epinephrine pen and keeping an eye out for the ants, there’s not much else that can be done. —Don Sweeney, Miami Herald, 10 June 2025

Other treatments for peanut allergy include: Avoiding foods that contain peanuts Receiving antibody injections (Xolair) to build up tolerance Preparing for a severe allergic reaction by carrying an emergency epinephrine autoinjector (EpiPen), or epinephrine nasal spray (Neffy). —Tom Gavin, EverydayHealth.com, 24 Apr. 2025

Word History

Etymology

International Scientific Vocabulary epi- + Greek nephros kidney — more at nephritis

First Known Use

1899, in the meaning defined above

Rhymes for epinephrine

• norepinephrine

Kids Definition

epinephrine

noun

ep·​i·​neph·​rine

ˌep-ə-ˈnef-rən

: a hormone of the adrenal gland acting especially on smooth muscle, causing narrowing of blood vessels, and raising blood pressure

called also adrenaline

Medical Definition

epinephrine

noun

epi·​neph·​rine

variants also epinephrin

ˌep-ə-ˈnef-rən 

: a colorless crystalline sympathomimetic hormone C₉H₁₃NO₃ that is the principal blood-pressure-raising hormone secreted by the adrenal medulla, is prepared from adrenal extracts or made synthetically, and is used medicinally especially to stimulate the heart during cardiac arrest and to treat life-threatening allergic reactions

called also adrenaline