tryptophan

noun

tryp·​to·​phan ˈtrip-tə-ˌfan How to pronounce tryptophan (audio)
variants or less commonly tryptophane
ˈtrip-tə-ˌfān How to pronounce tryptophan (audio)
: a crystalline essential amino acid C11H12N2O2 that is widely distributed in proteins

Examples of tryptophan in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
One amino acid found in eggs that’s especially important for immune function is tryptophan. — Mykenna Maniece, Vogue, 8 May 2026 In addition to melatonin, some foods contain tryptophan, an amino acid that can be converted into melatonin in the body, research shows. — The Washington Post, San Diego Union-Tribune, 7 Apr. 2026 However, there are not enough studies that have looked at the benefits of taking both tryptophan and magnesium together. — Emmanuella Ogbonna, Health, 17 June 2026 In addition to tryptophan, magnesium, and potassium, multiple other nutrients and compounds are key for sleep regulation. — Cristina Mutchler, Verywell Health, 27 June 2026 See All Example Sentences for tryptophan

Word History

Etymology

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

First Known Use

1890, in the meaning defined above

Time Traveler
The first known use of tryptophan was in 1890

Phrases Containing tryptophan

Browse Nearby Words

tryptone
tryptophan
trysail
See all Nearby Words

Cite this Entry

“Tryptophan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tryptophan. Accessed 7 Jul. 2026.

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Kids Definition

tryptophan

noun
tryp·​to·​phan ˈtrip-tə-ˌfan How to pronounce tryptophan (audio)
: 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 How to pronounce tryptophan (audio)
variants also tryptophane
-ˌfān How to pronounce tryptophan (audio)
: a crystalline essential amino acid C11H12N2O2 that is widely distributed in proteins
—abbreviation Trp

More from Merriam-Webster on tryptophan

Britannica.com: Encyclopedia article about tryptophan

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