HOW St. John's Wort WORKS
St. John's Wort constituents hyperforin and adhyperforin appear to modulate the effects of serotonin, dopamine, and norepinephrine, and may inhibit reuptake of these neurotransmitters to uplift mood. Most clinical research shows that taking St. John's wort as a single supplement can reduce depression and menopausal symptoms. One clinical study shows that a specific St. John's Wort extract containing 0.2 mg/mL hypericin, taken in doses of 20 drops three times daily for 2 months, significantly reduced the frequency, severity, and duration of hot flashes compared to placebo in premenopausal, perimenopausal, and postmenopausal women. Additional research shows that taking St. John's Wort 405-900 mg daily for 3-4 months reduces hot flashes by about 30% and improves sleep, quality of life, and psychological symptoms in menopausal women compared to placebo.