Relaxation.
Winding the nervous system down: the shift from wired to calm that most people chase in the evening. A handful of ingredients have real human research behind this, and plenty more ride the theme with little to show.
In context
About 1 in 3 US adults
report regular problems with stress or winding down.
CDC / national survey data
The ingredients studied for it.
Never ranked. Each has its own evidence page; the note is the essence, not a verdict.