theanine
noun
the·a·nine
ˈthē-ə-ˌnēn 
variants
or L-theanine
: an amino acid C7H14N2O3 found especially in green tea and used as a dietary supplement
Green tea, which is rich in a depression-fighting amino acid called theanine, has previously been lauded for its health benefits.—
Camilla Turner
Camilla TurnerExamples of theanine in a Sentence
Recent Examples on the Web
One cup of green or black tea contains roughly 25 to 60mg of L-theanine, so your nightly tea habit is a small but real contribution.
—Allison Palmer, Fort Worth Star-Telegram, 23 Apr. 2026
Many studies also combined L-theanine with other ingredients like GABA or magnesium, so standalone evidence is solid but still developing.
—Allison Palmer, Charlotte Observer, 23 Apr. 2026
That said, research on L-theanine in children is still limited.
—Allison Palmer, Sacbee.com, 23 Apr. 2026
Into that gap steps L-theanine, a natural sleep aid that’s been quietly building a case in the research.
—Allison Palmer, Kansas City Star, 23 Apr. 2026
See All Example Sentences for theanine
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Allison Palmer, Fort Worth Star-Telegram, 23 Apr. 2026
Many studies also combined L-theanine with other ingredients like GABA or magnesium, so standalone evidence is solid but still developing.
—Allison Palmer, Charlotte Observer, 23 Apr. 2026
That said, research on L-theanine in children is still limited.
—Allison Palmer, Sacbee.com, 23 Apr. 2026
Into that gap steps L-theanine, a natural sleep aid that’s been quietly building a case in the research.
—Allison Palmer, Kansas City Star, 23 Apr. 2026
See All Example Sentences for theanine
Cite this Entry
“Theanine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/theanine. Accessed 28 Apr. 2026.
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