L-Theanine is an amino acid found naturally in green and black tea leaves — it's part of the reason a cup of tea can feel calming without making you drowsy the way alcohol does. Unlike a sedative, L-Theanine doesn't force your body into sleep; it promotes a state of relaxed alertness by supporting alpha brain wave activity.

In the context of a bedtime routine, that translates to something very specific: quieting the racing-thoughts feeling that keeps a lot of people staring at the ceiling. It doesn't sedate you — it just takes the edge off the mental noise so your body can do what it already knows how to do, which is fall asleep.