- What is St. John's wort (Hypericum perforatum)-oral, and how does it work (mechanism of action)?
- What brand names are available for St. John's wort (Hypericum perforatum)-oral?
- Is St. John's wort (Hypericum perforatum)-oral available as a generic drug?
- Do I need a prescription for St. John's wort (Hypericum perforatum)-oral?
- What are the side effects of St. John's wort (Hypericum perforatum)-oral?
- What is the dosage for St. John's wort (Hypericum perforatum)-oral?
- Which drugs or supplements interact with St. John's wort (Hypericum perforatum)-oral?
- Is St. John's wort (Hypericum perforatum)-oral safe to take if I'm pregnant or breastfeeding?
- What else should I know about St. John's wort (Hypericum perforatum)-oral?
What is St. John's wort (Hypericum perforatum)-oral, and how does it work (mechanism of action)?
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.
What is the dosage for St. John's wort (Hypericum perforatum)-oral?
Dietary supplements such as St. John's wort are not regulated by the FDA, and are not subject to rigorous clinical studies that evaluate standardized drug dosages. Read product labels and discuss dosing with your doctor before taking this dietary supplement.
The most common dosage that has been used in the majority of studies is 0.3% hypericin or 5% hyperforin in a dosage of 300 to 400 mg three times daily.
Which drugs or supplements interact with St. John's wort (Hypericum perforatum)-oral?
: St. John's wort increases activity of several liver enzymes. Consequently, St. John's wort may decrease blood levels of drugs that are metabolized or broken-down by these enzymes. Examples of such drugs are warfarin (Coumadin), fluconazole (Diflucan), voriconazole (Vfend), itraconazole (Sporanox), fentanyl (Sublimaze), digoxin (Lanoxin), birth control pills and many other drugs.
St. John's wort should be avoided in patients taking prescription antidepressants due to the risk of serotonin syndrome. Symptoms of serotonin syndrome include agitation, hyperthermia (extreme body temperature), sweating, rapid heartbeat, and neuromuscular disturbances.
Additionally, St. John's wort may interact with other prescription medications. All patients should speak to their doctor or pharmacist before taking St. John's wort.

SLIDESHOW
Foods That Aren't as Healthy as You Think See SlideshowIs St. John's wort (Hypericum perforatum)-oral safe to take if I'm pregnant or breastfeeding?
Due to the lack of safety data, St. John's wort is not recommended during breastfeeding. It is not known if St. John's wort is excreted into breast milk.
Summary
St. John's Wort (Hypericum perforatum) is an herbal supplement used to treat anxiety and depression. Read product labels and discuss dosing with your doctor before taking this dietary supplement.
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Anxiety
Anxiety is a feeling of apprehension and fear characterized by symptoms such as trouble concentrating, headaches, sleep problems, and irritability. Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. Treatment for anxiety may incorporate medications and psychotherapy.
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Sleep Disorders
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Depression
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
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Teen Depression
Depression in teenagers may be caused by many factors. Symptoms of teen depression include apathy, irresponsible behavior, sadness, sudden drop in grades, withdrawal from friends, and alcohol and drug use. Treatment of depression in adolescents may involve psychotherapy and medications.
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Sleep Disorders in Children and Teenagers
Sleep needs in children and teenagers depend on the age of the child. Sleep disorders in children such as: sleep apnea, parasomnias, confusional arousals, night terrors, nightmares, narcolepsy, and sleepwalking which can affect a child's or teen's sleep. Healthy sleep habits and good sleep hygiene can help your infant, toddler, preschooler, tween, or teenager get a good night's sleep.
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Depression in Children
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Postpartum Depression
Postpartum depression is a form of depression that occurs within a year after delivery. It is thought that rapid hormone changes after childbirth may lead to depression. Symptoms of postpartum depression include crying a lot, headaches, chest pains, eating too little or too much, sleeping too little or too much, withdrawal from friends and family, and feeling irritable, sad, hopeless, worthless, guilty, and overwhelmed. Treatment typically involves talk therapy and medication.
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Insomnia Treatment (Sleep Aids and Stimulants)
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Treatment & Diagnosis
Medications & Supplements

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.