St. John's Wort (Hypericum perforatum)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD

    Dr. Charles "Pat" Davis, MD, PhD, is a board certified Emergency Medicine doctor who currently practices as a consultant and staff member for hospitals. He has a PhD in Microbiology (UT at Austin), and the MD (Univ. Texas Medical Branch, Galveston). He is a Clinical Professor (retired) in the Division of Emergency Medicine, UT Health Science Center at San Antonio, and has been the Chief of Emergency Medicine at UT Medical Branch and at UTHSCSA with over 250 publications.

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GENERIC NAME: Hypericum perforatum

BRAND NAME: St. John's Wort

DRUG CLASS AND MECHANISM: St. John's wort is a commonly used over-the-counter (OTC) dietary supplement that is used to treat mild depression, anxiety, and sleep disorders. St. John's wort is a plant that has bright yellow flowers. A number of compounds that have pharmacological activity including naphthodianthrones (hypericin, pseudohypericin, protohypericin, and cyclopseudohypericin), flavonoids (quercetin, rutin, and luteolin), hyperforin, several amino acidsand tannins have been isolated from St. John's wort.

The exact mechanism of how St. John's wort works to alleviate symptoms of depression is not understood. Hyperforin and hypericin are thought to be the major active components. Studies suggest that hyperforin affect serotonin, norepinephrine, and dopamine which are chemicals that affect mood. Other studies show that hypericum has weak effects on catechol-O-methyl transferase, an enzyme that is responsible for the breakdown of chemicals in the brain including serotonin, norepinephrine, and dopamine. Read product labels and discuss dosing with your doctor before taking this dietary supplement.

USED FOR: Capsules: 300 mg, Caplets: 300 mg are most common, but some preparations contain 325 mg.

SIDE EFFECTS: The most common side effects associated with St. John's wort treatment are

  • asfunction.

PRESCRIPTION: No

GENERIC AVAILABLE: Yes

STORAGE: Capsules and caplets should be stored at room temperature between 15 C and 30 C (59 F and 86 F).

PRESCRIBED FOR: St. John's wort is an over-the-counter (OTC) dietary supplement that is used for treatment of mild depression. It is also used to treat symptoms of mild anxiety and occasional episodes of sleep disturbances (insomnia), among others.

Medically Reviewed by a Doctor on 10/24/2014

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