tryptophan
noun
tryp·to·phan
ˈtrip-tə-ˌfan 
variants
or less commonly tryptophane
: a crystalline essential amino acid C11H12N2O2 that is widely distributed in proteins
Examples of tryptophan in a Sentence
Recent Examples on the Web
Turkey meat does indeed contain tryptophan, an amino acid that is associated with drowsiness when consumed.
—
Stephen C. George, Discover Magazine, 14 Nov. 2023
And researchers working on ME/CFS, a condition similar enough to Long COVID that many long-haulers meet its diagnostic criteria, have previously warned that tryptophan supplementation may be dangerous for patients.
—Jamie Ducharme, TIME, 23 Oct. 2023
Next, the researchers investigated whether tryptophan, an amino acid that contributes to serotonin production, could also be involved.
—Will Sullivan, Smithsonian Magazine, 18 Oct. 2023
The researchers believe leftover bits of the virus in the gastrointestinal tract cause the body to produce proteins that lead to inflammation and an inability to absorb tryptophan, an amino acid that's essential for the production and maintenance of neurotransmitters, including serotonin.
—Mary Kekatos, ABC News, 17 Oct. 2023
These chews feature chamomile and tryptophan alongside other natural ingredients known for their calming properties.
—Amber Smith, Discover Magazine, 5 Aug. 2023
High-quality protein is any protein that contains all of the nine essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine) that our bodies don’t make on their own.
—USA TODAY, 2 July 2023
Adding milk to your coffee could induce sleepiness since milk is a source of tryptophan, which could promote good sleep quality.
—Lacey Muinos, Better Homes & Gardens, 14 July 2023
Eating carbohydrates can increase the potency of tryptophan, which turns into melatonin and serotonin—hormones that help control sleep.
—Claire Bugos, Verywell Health, 13 July 2023
See More
Stephen C. George, Discover Magazine, 14 Nov. 2023
And researchers working on ME/CFS, a condition similar enough to Long COVID that many long-haulers meet its diagnostic criteria, have previously warned that tryptophan supplementation may be dangerous for patients.
—Jamie Ducharme, TIME, 23 Oct. 2023
Next, the researchers investigated whether tryptophan, an amino acid that contributes to serotonin production, could also be involved.
—Will Sullivan, Smithsonian Magazine, 18 Oct. 2023
The researchers believe leftover bits of the virus in the gastrointestinal tract cause the body to produce proteins that lead to inflammation and an inability to absorb tryptophan, an amino acid that's essential for the production and maintenance of neurotransmitters, including serotonin.
—Mary Kekatos, ABC News, 17 Oct. 2023
These chews feature chamomile and tryptophan alongside other natural ingredients known for their calming properties.
—Amber Smith, Discover Magazine, 5 Aug. 2023
High-quality protein is any protein that contains all of the nine essential amino acids (histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine) that our bodies don’t make on their own.
—USA TODAY, 2 July 2023
Adding milk to your coffee could induce sleepiness since milk is a source of tryptophan, which could promote good sleep quality.
—Lacey Muinos, Better Homes & Gardens, 14 July 2023
Eating carbohydrates can increase the potency of tryptophan, which turns into melatonin and serotonin—hormones that help control sleep.
—Claire Bugos, Verywell Health, 13 July 2023
See More
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'tryptophan.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
Word History
First Known Use
1890, in the meaning defined above
Phrases Containing tryptophan
Dictionary Entries Near tryptophan
Cite this Entry
“Tryptophan.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/tryptophan. Accessed 2 Dec. 2023.
Copy Citation
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
: 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
Love words? Need even more definitions?
Merriam-Webster unabridged
Share