5-HTP Standardized Griffonia Extract L-5-hydoxytryptophan (5-HTP) is a naturally occuring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitters, serotonin and melatonin, from tryptophan. Prompting feelings of well-being, alleviate anxiety and help you fall asleep. 100 mg 30 Capsules