Jarrow Formulas 5-HTP (5-Hydroxytryptophan) is an extract of Griffonia simplicifolia seeds from costal West Africa. 5-HTP is the direct metabolic precursor of serotonin and is important for the production of melatonin. 5-Hydroxytryptophan (5-HTP) is an amino acid that is the intermediate step between tryptophan and the important brain chemical serotonin. There is a massive amount of evidence that suggests that low serotonin levels are a common consequence of modern living. The lifestyle and dietary practices of many people living in this stress-filled era results in lowered levels of serotonin within the brain.