Gain emotional balance and learn to smile again with 5-HTP, the direct metabolic precursor of serotonin, commonly called the "happy" hormone. 5-HTP is also important for the production of melatonin, another important hormone that helps us enjoy restful sleep. Jarrow Formulas 5-HTP (5-Hydroxytryptophan) is an extract of Griffonia simplicifolia seeds from coastal West Africa.