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

Cottage cheese is also rich in tryptophan, a nutrient involved in the production of sleep-regulating hormones. — Sarah Jividen, Verywell Health, 8 Oct. 2026

According to the study, co-supplementation with tryptophan and magnesium can help reduce night awakenings and increase deep sleep. — Emmanuella Ogbonna, HEALTH, 2 Oct. 2026

In particular, the standard amino acid tryptophan was swapped for a synthetic counterpart called azatryptophan. — Mrigakshi Dixit, Interesting Engineering, 21 Sep. 2026

Mood Chicken contains the amino acid tryptophan, says Slayton, which can help build serotonin. — Embry Roberts, Martha Stewart, 30 Aug. 2026

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

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