5-HTP is a metabolite of tryptophan and precursor of serotonin and melatonin. Tryptophan5-HTP—>Serotonin—>Melatonin. 5-HTP plays a role in mood, sleep, anxiety, and pain sensation. Our 5-HTP is naturally derived from the seeds of the African plant Griffonia simplicifolia, and is combined with activated Vitamin B-6 as active P-5-P, an important co-factor in serotonin metabolism. Use with care when combining with SSRI's.