St. John's Wort

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    Last Updated: November 20, 2025

    St. John’s wort, also known by its Linnean name of Hypericum perforatum (HP), is an anti-depressant herb that is commonly used for its neurological effects. While it appears effective, it is well known to adversely interact with a variety of pharmaceuticals.

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    Dosage information

    The most common dosage of St. John's wort extract found in studies is 300mg, taken up to three times a day (for a total of 900 mg).[1]

    Examine Database: St. John's Wort

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    Examine Database References

    1. Depression Symptoms - Linde K, Berner MM, Kriston LSt John's wort for major depression.Cochrane Database Syst Rev.(2008-Oct-08)
    2. Depression Symptoms - Linde K, Berner M, Egger M, Mulrow CSt John's wort for depression: meta-analysis of randomised controlled trials.Br J Psychiatry.(2005-Feb)
    3. Depression Symptoms - Cui YH, Zheng YA meta-analysis on the efficacy and safety of St John's wort extract in depression therapy in comparison with selective serotonin reuptake inhibitors in adults.Neuropsychiatr Dis Treat.(2016)