HerbalFactors St. John’s Wort is a full-spectrum extract, containing guaranteed levels of 0.28% hypericin. Studies support the use of St. John’s Wort extract for helping promote healthy mood balance, relieve restlessness and nervousness, and relieve sleep disturbances associated with mood imbalance, as used in herbal medicine. People with diagnosed clinical depression or taking antidepressant medication should only use St. John’s Wort under the supervision of a health care practitioner.