Lifeplan 5-HTP 50mg (60 Tablets) 5-HTP (5-hydroxytryptophan) is a derivative of the essential amino acid, tryptophan, which is found in high protein foods and also the African plant Griffonia simplicifolia. 5-HTP (5-hydroxytryptophan) is a derivative of the essential amino acid, tryptophan, which is found in high protein foods and also the African plant Griffonia simplicifolia. Indigo Herbs has selected some of the best dietary supplements, teas & snacks from other leading health brands to complement our own extensive range of nutritionally dense superfoods, wholefoods.