tryptophan

noun

tryp·​to·​phan ˈtrip-tə-ˌfan 

variants or less commonly tryptophane

ˈtrip-tə-ˌfān 

: a crystalline essential amino acid C₁₁H₁₂N₂O₂ that is widely distributed in proteins

Examples of tryptophan in a Sentence

Recent Examples on the Web

In mice, Eggerthella has been found to lower key compounds that support gut and brain health, including tryptophan, which the body uses to produce serotonin. —Deirdre Bardolf, FOXNews.com, 18 Oct. 2025

In addition, dietary tryptophan – an amino acid found in foods such as poultry, eggs, tofu and seeds – is metabolized into compounds that activate the aryl hydrocarbon receptor, further boosting Treg cell activity and protecting against gut inflammation. —Mitzi Nagarkatti, The Conversation, 10 Oct. 2025

Turkey Turkey often gets credit for the post-Thanksgiving crash, thanks to its tryptophan content. —Anthea Levi, Health, 26 Sep. 2025

Roasted pumpkin seeds contain magnesium and tryptophan, two nutrients linked to better sleep. —Abby Norman, Verywell Health, 24 Sep. 2025

Word History

Etymology

borrowed from German Tryptophan, from tryptisch tryptic + -o- -o- + -phan -phane

First Known Use

1890, in the meaning defined above

Phrases Containing tryptophan

• L-tryptophan

Rhymes for tryptophan

• boffin
• coffin
• offen
• often
• soften

Kids Definition

tryptophan

noun

tryp·​to·​phan ˈtrip-tə-ˌfan 

: an amino acid that is found in many proteins and is necessary for life but cannot be manufactured by the human body and must be obtained in food

Medical Definition

tryptophan

noun

tryp·​to·​phan ˈtrip-tə-ˌfan 

variants also tryptophane

-ˌfān 

: a crystalline essential amino acid C₁₁H₁₂N₂O₂ that is widely distributed in proteins

—abbreviation Trp