Drinking evening tea (warm, not brewed hot) has long been a daily habit for me. In the past, I struggled to fall asleep and also woke up several times during the night. With regularly drinking the tea, my sleep has greatly improved.
In science, to be convinced of such an effect, one would like to have a so-called „negative control“… but who would willingly give up good sleep for that? Not me, but funnily enough, I unintentionally got a negative control anyway: recently I again had difficulty falling asleep and it reminded me of earlier times. I thought it might be the heat… and then it occurred to me: I had forgotten the tea! The next evening it was just as warm, but with the tea, falling asleep was no problem :-).