5-hydroxy-l-tryptophan (5-HTP) is a chemical byproduct of the protein building block L-tryptophan. It is produced commercially from the seeds of an African plant known as Griffonia simplicifolia. In vivo, it is produced from tryptophan by tryptophan hydroxylase (TPH), and its decarboxylation yields serotonin (5-hydroxytryptamine, 5-HT), a monoamine neurotransmitter involved in the modulation of mood, cognition, reward, learning, memory, sleep, and numerous other physiological processes. 5-HTP is both a drug and a natural component of some dietary supplements, and occurrence in both synthetic tryptophan and 5-HTP of toxic impurities has caused eosinophilia myalgia syndrome cases[1].
