What is in warm milk that helps you fall asleep?

Does warming milk change the chemistry of the milk? Why does this help you sleep?What is in warm milk that helps you fall asleep?
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Tryptophan is the main reason; warmth is the other.
Nite-nite ......
-MM
cause its warm and it relaxes u
Actually it doesnt have to be warm to have the same effects . It helps babies cause you always warm their bottles.
I think the calcium is enhanced. Calcium can be used as a natural relaxant.
Calcium girl, calcium is a mild nerve relaxant, unless you're lactose intolerant that is.
Milk contains L-Tryptophan, a natural sedative. Warming milk doesn't create it or make it more potent, but a warm drink is comforting - maybe it reminds us of our babyhood. Don't boil it, though, just warm it:-)