5-Hydroxy Tryptophan (HTP) is a natural precursor to seratonin the neurotransmitter that helps maintain a healthy, calm mood & sleep pattern. Veganicity 5-HTP Complex is high strength formulation that combines 100mg of 5-HTP with B vitamins & the minerals Magnesium & Zinc. All known to help induce a calming effect & help maintain healthy sleep patterns.