L-Tryptophan

USE: Your body uses the amino acid tryptophan -- sometimes called L-tryptophan -- to make the B vitamin niacin as well as melatonin and serotonin. Melatonin and serotonin are chemicals called neurotransmitters that the nervous system uses as messengers. Both help you sleep and affect your moods. Tryptophan helps with insomnia, depression, anxiety and Migraines.
SOURCE: As an amino acid, tryptophan is found primarily in foods that are high in protein, such as meat, eggs, cheese and milk, but it can also be found in vegetable proteins such as the protein in potatoes, brown rice, soybeans and peanuts.