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

Physical activity such as running, brisk walking, swimming, dancing, and bicycling raises serotonin levels, reduces cravings, and lowers PMS symptoms. —Anna Giorgi, Verywell Health, 31 Mar. 2025

The key biological mechanism behind this effect appears to be a drop in serotonin levels. —Ron Estes, MSNBC Newsweek, 28 Mar. 2025

Consider, for example, how people tend to be more collaborative in the morning due to higher dopamine and serotonin levels. —Matt Abrahams, TIME, 25 Mar. 2025

Spending time outdoors in spring while using CBD or marijuana responsibly may further reduce stress, boost serotonin levels, and promote relaxation. —Tribune Content Agency, Mercury News, 25 Mar. 2025

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