An anthroquinone derivative that is naturally found in the flower of H. perforatum (St. John’s wort) and has antidepressant, antiviral, and anticancer activities.^1,2 Hypericin inhibits neuronal uptake of serotonin, norepinephrine, dopamine, GABA and L-glutamate, contributing to its antidepressant effects.³ It exerts broad spectrum phototoxic affects (IC50 = 140 - 1,570 nM) through induction of apoptotic signaling and formation of reactive oxygen species (ROS) in cancer cells.⁴ Hypericin also has in vitro activity, which can be enhanced with photo-activation, against a variety of viruses including HIV, influenza virus, hepatitis C, murine cytolomegalovirus, and herpes viruses.⁵