L-tryptophan is an exogenous amino acid (otherwise necessary), i.e. one that must be supplied to the body because it cannot produce it by itself. Tryptophan plays a very important role in the central nervous system because it is converted to serotonin and melatonin. Tryptophan is a precursor in the synthesis of serotonin and melatonin. Serotonin is a biologically active substance; is an important neurotransmitter that is responsible for the presence of emotional states (e.g. anger, good mood, sleep) and sexual behavior. So our well-being depends on the presence of serotonin. In contrast, melatonin, which is secreted during sleep, is responsible for the occurrence of circadian rhythm and biological clock. Is often referred to as the “sleep hormone”. The conversion of tryptophan to serotonin and melatonin takes place only in the central nervous system.
