theanine

noun

the·​a·​nine ˈthē-ə-ˌnēn 

variants or L-theanine

ˈel-ˈthē-ə-ˌnēn 

: 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

Examples of theanine in a Sentence

Recent Examples on the Web

Top mood balance vitamin for kids This blend includes a child-appropriate blend of magnesium, L-theanine and lemon balm. —Bestreviews, Chicago Tribune, 8 May 2026

It’s formulated with a blend of chaga, lion’s mane, cordyceps and reishi mushrooms, plus adaptogens lemon balm, passion flower, L-theanine, mucuna pruriens, ashwagandha, holy basil, magnolia bark and wild jujube. —Ryan Brennan, Charlotte Observer, 7 May 2026

The caffeinated formula adds natural caffeine from green coffee bean extract — typically around 150 mg per serving — along with L-theanine, included to smooth out jitteriness. —Sacbee.com, 6 May 2026

Each can contains a lovely 60 mg of caffeine and 30 mg of L-theanine—just enough to add a brighter sheen in the afternoon. —Alaina Chou, Bon Appetit Magazine, 30 Apr. 2026

Word History

First Known Use

1950, in the meaning defined above

Rhymes for theanine

• affine
• airline
• align
• aline
• assign
• baseline
• beamline
• benign
• bloodline
• bovine
• brucine
• byline