St. John's wort
Hypericum perforatum
Hypericum perforatum, commonly known as St. John's wort, is a traditional medicinal plant used in various European and folk medicine practices for treating mild depressive episodes and low mood. It has also been traditionally applied topically to manage minor wounds and burns. Scientific evidence suggests that Hypericum perforatum may have some benefits, particularly in reducing oral bacteria associated with dental plaque and gingivitis. Studies indicate synergistic activity against certain bacteria when combined with other essential oils. Additionally, research shows potential for improving sleep quality through adenosine and melatonin receptor signaling, though specific dosages are not well-documented. Safety concerns include photosensitivity, where the skin becomes more sensitive to sunlight, necessitating caution in sun exposure. Hypericum perforatum can interact with several medications; it may reduce the effectiveness of warfarin by inducing CYP3A4 and P-glycoprotein enzymes, potentially lowering drug blood levels and efficacy. It also interacts with oral contraceptives, possibly reducing their contraceptive effect due to enzyme induction. Furthermore, combining Hypericum perforatum with selective serotonin reuptake inhibitors (SSRIs) could lead to an increased risk of serotonin syndrome due to additive serotonergic effects.
- Traditionally for
- mild depressive episodes / low mood · minor wounds and burns (topical, traditional)
- Traditions
- Western phytotherapy
- Best evidence
- B
- Cautions
- ⚕ 3 ⚠ 1
Informational only. Traditional use does not mean proven effectiveness. Evidence and safety vary — check the cited sources.
Traditional use
What the science says
- The study found that Hypericum perforatum extract gum significantly reduced Streptococcus mutans count, plaque index, and gingival bleeding compared to gum without the extract, though both gums increased salivary pH.
- HME significantly reduced sleep onset latency and prolonged total sleep time in mice, suggesting effects mediated through adenosine and melatonin receptor signaling.
- Both Hypericum perforatum and Chaihu Shugan San alleviated depressive-like behaviors in a chronic stress model, with distinct molecular mechanisms involving lipid metabolism and broader metabolic processes.
- Hypericum perforatum and Glycyrrhiza glabra treatments reduced MAO-A activity, restored ERβ expression, and improved mitochondrial function in estrogen-deficient conditions without explicit dose or recommendation.
- Hypericum perforatum and Achillea millefolium essential oils showed synergistic activity against Staphylococcus epidermidis in specific oil mixtures.
Safety & toxicity
- photosensitivity — skin becomes more sensitive to sunlight
Drug interactions
- warfarin — induces CYP3A4 / P-glycoprotein → lowers drug blood levels and effect
- oral contraceptives — enzyme induction → reduced contraceptive efficacy, breakthrough bleeding
- SSRI antidepressants — additive serotonergic effect → risk of serotonin syndrome
Frequently asked questions
What is St. John's wort?
St. John's wort (Hypericum perforatum) is a plant documented in FolkKB's traditional-medicine reference, drawn from sourced literature and cross-checked against the evidence.
What is St. John's wort traditionally used for?
Traditional sources record St. John's wort for: mild depressive episodes / low mood, minor wounds and burns (topical, traditional). This reflects traditional use, not a proven medical treatment.
Which traditions use St. John's wort?
St. John's wort appears in these traditions in our sources: Western phytotherapy.
What does the scientific evidence say about St. John's wort?
5 sourced findings are recorded for St. John's wort; the strongest carries evidence grade B. For example: The study found that Hypericum perforatum extract gum significantly reduced Streptococcus mutans count, plaque index, and gingival bleeding compared to gum without the extract, though both gums increased salivary pH.
How strong is the evidence for St. John's wort?
The strongest finding for St. John's wort carries evidence grade B — moderate evidence. Grades run A (strongest) to D (preliminary or traditional).
Is St. John's wort safe? What are the side effects?
Reported effects associated with St. John's wort include: photosensitivity — skin becomes more sensitive to sunlight. This is informational only — consult a qualified professional before use.
Does St. John's wort interact with medications?
Recorded drug interactions for St. John's wort involve: warfarin, oral contraceptives, SSRI antidepressants. Tell your doctor or pharmacist about any herb you take.
What are the common names of St. John's wort?
St. John's wort is also known as: зверобой, Millepertuis.
Is St. John's wort a proven treatment?
No. FolkKB is informational only. Traditional use and early findings are not proof of efficacy or safety — consult a qualified professional and never self-treat.
Sources
- T1 EMA HMPC monograph: Hypericum perforatum (St. John's wort) © EU/EMA — reproduced with attribution
- T1 LiverTox: St. John's Wort public domain
- T2 NCCIH: St. John's Wort public domain (attribute NCCIH)
- T2 Clinical Assessment of the Effect of Hypericum perforatum Chewing Gum on Salivary Streptococcus mutans Count, pH, Plaque Index, and Gingival Bleeding: A Randomized Clinical Trial. literature abstract metadata
- T2 Chemical Composition and Synergistic Antimicrobial Activity of Hypericum perforatum and Achillea millefolium Essential Oils Against Wound-Associated Microorganisms. literature abstract metadata
- T2 Hypericum perforatum L. and Glycyrrhiza glabra L. preserve cardiac mitochondrial redox homeostasis in E2 deficiency via ERβ-MAO-A modulation. literature abstract metadata
- T2 Integrative Proteomics Reveals Distinct Lipid Metabolic and Gut Microbiota-Associated Antidepressant Mechanisms of Two Herbal Medicines in a Chronic Stress Model. literature abstract metadata
- T2 Hypnotic Effects of Hypericum perforatum L. and Melissa officinalis L. Through Adenosine and Melatonin Receptors. literature abstract metadata