Tea contains L-theanine

L-theanine prevents glutamate from binding

Glutamate has lots of signaling meanings in the body, but mostly it means “prepare for fight or flight”.

Glutamate is one chemical transformation step from being GABA

GABA also has lots of different receptor contexts, but mostly means “chill”

Glutamate is the oldest intercellular signal molecule in evolution. Sponges have glutamate signaling. For sponges it means “swish the water around”, which is the closest thing a sponge had to “fight or flight”.

Anyway, yes. Tea has L-theanine, which is an amazing psychoactive chemical.

For example, scientific studies have found when people take a dose of L-theanine, it increases the amplitude and predominance of alpha waves in their brain.

Alpha waves are associated with “a calm and ready state of alertness”.

Meditation is also found to increase alpha wave activity.