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

Research suggests changes in brain chemistry involving neurotransmitters such as serotonin, dopamine and norepinephrine can cause depressive symptoms, says Noorlander. —Daryl Austin, USA Today, 14 Mar. 2026

The untitled track comes with a serotonin-providing video of a person—perhaps the Norwegian singer/composer herself—skipping down a road carrying a baby, with a brief cameo from a similarly cheerful dog. —Jazz Monroe, Pitchfork, 13 Mar. 2026

Using trendy spring nail colors like misty blue, lilac, and bright orange is key to a pretty manicure that’s not only going to be the envy of your friends, but also give you a boost of serotonin, too. —Audrey Noble, Vogue, 8 Mar. 2026

Bouquets, real, faux, or on your manicure, are an instant serotonin booster. —Ariel Wodarcyk, InStyle, 5 Mar. 2026

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