St. John’s Wort

St. John’s wort is found in Europe and in the United States, growing abundantly in southern Oregon and northern California. In ancient Greece, St. John’s wort was used for various ailments. Presently, St. John’s wort is used in Europe and the United States for depression.

The major compounds in St. John’s wort include hypericin and other dianthrones, flavonoids, xanthones, and hyperforin. While it was previously thought that the therapeutic actions of this herb were due to hypericin and the inhibition of the enzyme monoamine oxidase, current research has challenged this view, focusing on other constituents, such as hyperforin and flavonoids. Test tube studies suggest that St. John’s wort extract may promote antidepressant effects by inhibiting the reuptake of neurotransmitters such as serotonin, norepinephrine, and dopamine. This may increase the availability of these neurotransmitters in the brain. This activity is thought to be associated with hyperforin.

The standard recommendation is 450 mg to 900 mg per day of St. John’s wort standardized extract, depending on the severity of the condition. Results may be seen as early as two weeks. The duration of use should always be monitored by a health care professional.