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

Children who have an allergy that could cause anaphylaxis symptoms such throat swelling and other severe reactions have long had to carry an epinephrine injectable pen with them or have one stored at school. —Nicole Villalpando, Austin American Statesman, 2 July 2025

The traditional treatment for anaphylaxis is a shot of the hormone epinephrine into the leg muscle. —Breanne Hayes Haney, The Conversation, 14 Apr. 2025

The algorithm can predict the reaction’s severity, alert the individual and caregivers, and automatically inject epinephrine when necessary. —David Henkin, Forbes.com, 20 May 2025

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

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