norepinephrine

noun

nor·​epi·​neph·​rine ˈnȯr-ˌe-pə-ˈne-frən How to pronounce norepinephrine (audio)
: a monoamine C8H11NO3 that is a neurotransmitter in postganglionic neurons of the sympathetic nervous system and in some parts of the central nervous system, is a vasopressor hormone of the adrenal medulla, and is a precursor of epinephrine in its major biosynthetic pathway

Examples of norepinephrine in a Sentence

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That’s because vagus nerve stimulation might work in part by raising brain levels of norepinephrine – and people with Alzheimer’s have too little norepinephrine in their brains. — Elizabeth Riley, The Conversation, 26 Mar. 2026 Research also suggests changes in brain chemistry involving neurotransmitters such as serotonin, dopamine and norepinephrine can cause depressive symptoms. — Sara Moniuszko, USA Today, 30 June 2026 Under acute stress, Arnsten's work shows, high levels of norepinephrine and dopamine weaken the prefrontal cortex while strengthening the more primitive, reflexive responses governed by the amygdala. — Kwame Christian Esq, Forbes.com, 25 June 2026 According to Plunge, cold-water immersion triggers norepinephrine, a chemical messenger that delivers a burst of energy while sharpening focus. — Samantha Agate, Charlotte Observer, 6 May 2026 See All Example Sentences for norepinephrine

Word History

First Known Use

1937, in the meaning defined above

Time Traveler
The first known use of norepinephrine was in 1937

Rhymes for norepinephrine

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Browse Nearby Words

norephedrine
norepinephrine
norethindrone
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Cite this Entry

“Norepinephrine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/norepinephrine. Accessed 8 Jul. 2026.

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Kids Definition

norepinephrine

noun
nor·​epi·​neph·​rine ˈnȯ(ə)r-ˌep-ə-ˈnef-rən How to pronounce norepinephrine (audio)
: a hormone that causes blood vessels to contract and helps to transmit nerve impulses in the sympathetic nervous system and in some parts of the central nervous system

Medical Definition

norepinephrine

noun
nor·​epi·​neph·​rine ˌnȯr-ˌep-ə-ˈnef-rən How to pronounce norepinephrine (audio) -rēn How to pronounce norepinephrine (audio)
: a catecholamine C8H11NO3 that is the chemical means of transmission across synapses in postganglionic neurons of the sympathetic nervous system and in some parts of the central nervous system, is a vasopressor hormone of the adrenal medulla, and is a precursor of epinephrine in its major biosynthetic pathway

called also arterenol, noradrenaline

see levophed

More from Merriam-Webster on norepinephrine

Britannica.com: Encyclopedia article about norepinephrine

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