5-HTP is an amino acid which occurs naturally. It is sold in many countries including the United States not only as a diet supplement but also as an appetite suppressant, antidepressant and to abet sleep. 5 –HPT affects the serotonin synthesis present in the central nervous system and causes psychoactiveness. 5 – HPT is believed to increase the production of neurons in the serotonin; this in turn increases serotonin release and causes mood imrpovement. When administered along with decarboxylase inhibitor like carbidopa it increases the level of plasma. Nevertheless, several studies have come up with contradictory reports. While some has come up with theories about its effectiveness even in the absence of decarboxylase inhibitor, others indicate that 5 – HPT when combined with carbidopa could cause conditions similar to scleroderma.