Herbarium of the Ancients — Detailed Monograph

St. John's Wort

Hypericum perforatum

Please read before use: the information below describes traditional and informational uses — it does not replace the advice of a healthcare professional. In case of doubt, pregnancy, breastfeeding, ongoing treatment, or use in children, seek advice before use.

Enhanced precautions for this plant: St. John's wort is known to interact with numerous medications (oral contraceptives, anticoagulants, antidepressants, immunosuppressants, etc.) by reducing their effectiveness: medical or pharmaceutical advice is essential before any internal use. The plant may cause photosensitization of the skin; it is recommended to avoid prolonged sun exposure after application or ingestion of St. John's wort. Internal use is not recommended during pregnancy or breastfeeding, or in children, without advice from a healthcare professional. Do not combine with ongoing medication without first consulting a doctor or pharmacist.

Infused Oil — Flowers

Red St. John's wort oil (topical use)

Fresh flowers are macerated for several weeks in a vegetable oil, exposed to light, until a characteristic red tint is obtained. It is then filtered before local application on intact or slightly irritated skin. Dosage must be validated with a healthcare professional or recognized pharmacopoeia before use.

Infusion — Flowers

Traditional infusion of flowering tops

Dried flowers are infused in simmering water for about ten minutes, away from direct light. This preparation was traditionally consumed in the evening or after meals, with professional advice in case of ongoing treatment. Dosage must be validated with a healthcare professional or recognized pharmacopoeia before use.

Tincture — Flowers

Alcoholic tincture of flowers

Fresh flowers are macerated in alcohol of sufficient strength for several weeks, away from light, then filtered. This concentrated form, requiring more careful use, necessitates guidance from a qualified professional. Dosage must be validated with a healthcare professional or recognized pharmacopoeia before use.

Where to Find It

Obtaining the Plant

Wild St. John's wort is found in meadows, embankments, and sunny edges throughout Europe, as well as cultivated in some medicinal plant gardens; it is also available dried in herbal shops in the form of flowers or galenic preparations.

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