Serotonin hydrochloride is the salt form of Serotonin, a monoamine neurotransmitter biochemically derived from tryptophan. This neurotransmitter is located in the central nervous system and functions as an endogenous SR (serotonin receptor) agonist in a variety of biochemical processes. In the majority of the human bodies, serotonin is located in enterochromaffin (”Kulchitsky cells”). Serotonin is found in the gastrointestinal tract and platelets. Furthermore, Serotonin functions as a growth factor in some cells and facilitates wound healing in conjunction with platelets. Serotonin is thought to be a key component in the regulation of moods, cognition, and personality traits. As a result, this compound is essential in studying the variations in these traits. A tryptophan based amino acid neurotransmitter.