serotonin

noun

se·​ro·​to·​nin ˌsir-ə-ˈtō-nən 

ˌser-

: a phenolic amine neurotransmitter C₁₀H₁₂N₂O that is a powerful vasoconstrictor and is found especially in the brain, blood serum, and gastric mucous membrane of mammals

Examples of serotonin in a Sentence

Recent Examples on the Web

Stress also lowers levels of serotonin, which helps facilitate gut motility and regular bowel movements. —Brittany Dube, Health, 8 Feb. 2025

Anti-Nausea Delta-8 flower might regulate nausea by modulating serotonin receptor activity. —Rowan Briggs, The Mercury News, 17 Jan. 2025

SNRIs work by blocking this absorption or inhibiting it, allowing more serotonin and norepinephrine to remain active and available in the brain and transmit easier from nerve to nerve. —Mary Walrath-Holdridge, USA TODAY, 13 Dec. 2024

These medicines mainly target the brain to increase serotonin signaling but also end up impacting the gut’s serotonin signaling mechanisms. —Anuradha Varanasi, Forbes, 26 Dec. 2024

Word History

Etymology

sero- + ton(ic) entry 2 or tone entry 1 + -in entry 1, probably after angiotonin, earlier name for angiotensin — more at angiotensin

Note: Term introduced by Maurice M. Rapport, Arda Alden Green and Irvine H. Page in "Crystalline serotonin," Science, vol. 108, Issue 2804 (September 24, 1948), pp. 329-330: "The general behavior of the crystalline substance is suggestive of its homogeneity. We would like provisionally to name it serotonin, which indicates that its source is serum and its activity is one of causing constriction."

First Known Use

1948, in the meaning defined above

Phrases Containing serotonin

• selective serotonin reuptake inhibitor

Rhymes for serotonin

• calcitonin
• digitonin
• melatonin
• kronen
• onan
• phonon
• ronin
• santonin

Medical Definition

serotonin

noun

se·​ro·​to·​nin ˌsir-ə-ˈtō-nən  ˌser- 

: a phenolic amine neurotransmitter C₁₀H₁₂N₂O that is a powerful vasoconstrictor and is found especially in the brain, blood serum, and gastric mucous membrane of mammals

called also 5-HT, 5-hydroxytryptamine