Warm milk works magical for the sleep. People use it a natural remedy for variou sleep disorders. Milk contains a biochemical agent that is called L-tryptopha. L-tryptophan is a type of amino acid that is essential in the body. This amino acid can trigger the natural release of melatonin in the body. Melatonin is a hormone released from the pineal gland, which is responsible for regulating the body's internal body clock, which is responsible for the sleep and wake cycle of a person.