L-theanine is an amino acid commonly found in tea leaves (Camellia sinensis). It’s known for its relaxing and calming effects on the brain without causing drowsiness. This amino acid can cross the blood-brain barrier, allowing it to interact with brain receptors and neurotransmitters. Researchers believe L-theanine promotes relaxation by increasing the production of gamma-aminobutyric acid (GABA), serotonin, and dopamine. These neurotransmitters play a role in regulating mood and stress levels. Here are some of the potential benefits of L-theanine: stress reduction, improved focus and attention, better sleep, anxiety management, cardiovascular support, immune support, and brain protection.