Ingredient name: L-theanine
Chemical formula: C7H14N2O3
Food and Drug Administration Recommended Daily Intake: No recommended daily intake
Quantity of L-theanine included in one bottle of Coffiest: 75 mg
First isolated in 1950, L-theanine is an amino acid found in the leaves of the tea plant (camellia sinensis) which has been shown to temporarily enhance concentration and reaction time in users. Although theanine has little effect when consumed on its own, it shares space in the tea leaf with caffeine, the presence of which amplifies theanine’s cognition-boosting properties. In addition, theanine seems to have a calming effect which may help mitigate the less desirable side effects of caffeine consumption.
Theanine, as an analog of glutamate, can be converted into the latter in the liver or intestine. Additionally, theanine can bypass digestion and enter the brain directly, where its structural similarity allows it to bind with and act on glutamate receptors.
Reason this form chosen:
L-theanine is the more frequently occurring of the theanine molecule’s two forms, and as such its properties have been more thoroughly researched. Only L-theanine is produced by tea plants, but its mirror-image version D-theanine can be synthesized as well. Although D-theanine is also in use as a theanine supplement, it has been the subject of far less study, and its effects may differ from those of L-theanine.