Origin and history
Tryptophan is an essential amino acid, meaning that the body cannot produce it: it must be obtained from food. Discovered in the early 20th century, it quickly attracted scientific interest because it is the precursor to two molecules that are key to well-being: serotonin, a neurotransmitter involved in relaxation and mood, and melatonin, a sleep hormone. Tryptophan is now known to be an essential nutrient for emotional balance, sleep, and the overall functioning of the nervous system.