5-HTP is an amino acid that acts as a precursor to serotonin, a neurotransmitter that regulates appetite, mood, feelings, behaviour, and sleep. The body produces 5-HTP from the amino acid tryptophan, whereas 5-HTP supplements are composed from the seeds of Griffonia simplicifolia plant. Natrol 5-HTP helps conduct healthy mood, adverise relaxation and sleep, and complete healthy appetite control. visit us: http://www.tasmanhealth.co.nz/natrol-5-htp-time-re lease-100mg/ for more details!!