L-theanine is a natural amino acid found in green tea. Chemically, L-theanine is similar in structure to glutamate, glutamine, and gamma-aminobutyric acid (GABA). 

Due to its exceptional bioavailability and uptake across the blood-brain barrier, supplementing with L-theanine readily induces a variety of nootropic effects, promoting relaxation without the drowsiness

Ingredient Name:

Theanine (AKA: L-Theanine, 5-N-Ethyl-Glutamine)


- Promotes relaxation without drowsiness

- Enhances cognitive function

- Reduces negative effects of caffeine, such as excessive jitteriness and headaches 

How To Take:

L-Theanine tends to be taken in the dosage of 100-200mg, usually alongside caffeine


More Information:

Studies on L-Theanine: https://examine.com/supplements/theanine/

Juneja, L. R., Chu, D. C., Okubo, T., Nagato, Y., & Yokogoshi, H. (1999). L-theanine—a unique amino acid of green tea and its relaxation effect in humans. Trends in Food Science & Technology, 10(6), 199-204.

- Kim, T. I., Lee, Y. K., Park, S. G., Choi, I. S., Ban, J. O., Park, H. K., ... & Hong, J. T. (2009). l-Theanine, an amino acid in green tea, attenuates β-amyloid-induced cognitive dysfunction and neurotoxicity: reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-κB pathways. Free Radical Biology and Medicine, 47(11), 1601-1610.

Song, C. H., Jung, J. H., Oh, J. S., & Kim, K. S. (2003). Effects of theanine on the release of brain alpha wave in adult males. Korean Journal of Nutrition, 36(9), 918-923.

Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., & Scholey, A. B. (2008). The effects of L-theanine, caffeine and their combination on cognition and mood. Biological psychology, 77(2), 113-122.

Lu, K., Gray, M. A., Oliver, C., Liley, D. T., Harrison, B. J., Bartholomeusz, C. F., ... & Nathan, P. J. (2004). The acute effects of L‐theanine in comparison with alprazolam on anticipatory anxiety in humans. Human Psychopharmacology: Clinical and Experimental, 19(7), 457-465.