Tryptophan (1-tryptophan) is an essential amino acid necessary for the production of serotonin and melatonin. Tryptophan can soothe nerves and anxiety, reduce carbohydrate cravings, relieve pre-menstrual symptoms, and enhance relaxation and sleep. By helping to boost serotonin production, tryptophan can be used as an adjunct therapy in relieving depression. Unavailable in the US market until recently, tryptophan is back so you can once again take advantage of its wonderful soothing mood-lifting properties.
Wexler, Barbara "Tryptophan Powerful Serotonin Booster". Woodland Publishing, 2008. 30 pages. (Paper) ISBN# 978-1-58054-121-3.