ChEBI: Serotonin is a primary amino compound that is the 5-hydroxy derivative of tryptamine. It has a role as a human metabolite, a mouse metabolite and a neurotransmitter. It is a monoamine molecular messenger, a primary amino compound, a member of phenols, a member of hydroxyindoles and a member of tryptamines. It derives from a tryptamine. It is a conjugate base of a serotonin(1+).