St. John's Wort has emerged as the leading botanical product to support mood and well-being. St. John's Wort contains numerous substances, including hypericin, which have been shown to modulate neurotransmitter activity as well as other aspects of neuroendocrine function. Included in these effects are inhibition of both monoamine oxidase and serotonin reuptake. Extracts standardized for 0.3% hypericin content are routinely used in clinical studies of St. John's Wort.
