Flexi Says: Serotonin is a neurotransmitter produced by nerve cells in the brain It is believed to play an important role in regulation of mood, emotions and appetite. Serotonin is synthesized from the amino acid tryptophan and is chemically known as 5-hydroxy tryptamine (5-HT). Tryptophan deficiency can lead to low levels of serotonin and cause depression and other mood disorders.
