Hypericin is a chemical compound found in some herbal products. It is found in particularly high concentration in the herb St. John's Wort, and is thought to be the active ingredient that gives this herb its beneficial effects.
Studies on hypericin have shown that it works on certain types of cells to increase the amount of serotonin and dopamine.
Because of its ability to increase dopamine (which can raise blood pressure), products containing hypericin should be used with caution in patients with high blood pressure.

