The red oil is also used externally to bring down inflammation, such as hemorrhoids. St. John's wort is also used as a diuretic. St. John's wort is derived from Hypericum perforatum. This aromatic perennial herb with golden flowers is a member of the Hypericaceae family. St. John's wort gained its namesake from the age-old story that the plant supposedly sprung from the blood of St. John the Baptist when he was beheaded.
Parts used are the leaves and flowering tops.
St. John's wort is the most commonly prescribed antidepressant in Germany, with two to three million prescription written every year. Relevant Studies SAD and St. John's wort. J Geriatr Psychiatry Neurol, Oct. 1994. Serotonin and St. John's wort. According to this German study, the anti-depressant activity of St. John's wort extract is due to an inhibition of the uptake of the neurotransmitter serotonin by receptors in the brain.