SUGGESTED BUT UNPROVEN USES: SEASONAL AFFECTIVE DISORDER
ADJUNCTIVE USE - CAUTION
NEGATIVE EVIDENCE
MAJOR RISKS
DRUG INTERACTIONS
SIDE EFFECTS
DOSAGE
RESEARCH
Hypericum perforatum, commonly called St. John’s wort, hypericum, Klamath weed, or goat
weed, is a perennial plant with yellow flowers whose medicinal uses were first recorded in
ancient Greece. It is the most studied and one of the most popular CAM products used for
mental health conditions. It is a common roadside plant throughout the United States,
Europe and Asia and has a long history of folk use in many cultures. The prevalent name St.
John’s wort apparently refers to John the Baptist, as the plant blooms around the time of
the feast of St. John the Baptist in late June in the northern hemisphere.
Research on St. John’s wort has be hampered by the intermittent course of most depression
(its tendency to come and go), variability in the quality of extracts, use of low doses of the
