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

Research has found that higher levels of stress hormones, like cortisol and epinephrine, are linked with a greater risk of developing high blood pressure over time.10 Finding a few minutes each morning to participate in a stress management activity can be healthy for your blood pressure levels. —Karen Berger, Verywell Health, 17 Sep. 2025

Colorado capped the cost of insulin and epinephrine shots to treat severe allergic reactions in state plans, but couldn’t require the same for plans the state doesn’t oversee. —Meg Wingerter, Denver Post, 14 Sep. 2025

People who experience severe allergic reactions may carry epinephrine autoinjectors, such as EpiPens, to stop anaphylaxis. —Karissa Waddick, USA Today, 29 Aug. 2025

Current emergency treatments for severe allergic reactions, such as epinephrine, are aimed at quickly reversing symptoms once anaphylaxis starts. —Hannah Millington, MSNBC Newsweek, 28 Aug. 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