St John’s Wort – Hypericum Perforatum

By Sharn Harper

Common names:

Chase Devil, Goatweed, St Joan’s Wort, and Tipton’s weed.

Habitat and Growing Conditions: 

St John’s Wort is native to Europe and Asia. In Australia, where it has been introduced, St john’s Wort is classed as a weed as it spreads easily. The plant can lay dormant for 20 years and when livestock feed on it causes a myriad of health issues including photosensitivity and heart problems.  St John’s wort is a perennial, it grows erect, up to 90cm high, and prefers light sandy soil and regular watering or at least 60cm of rain a year.  Its roots will grow deep but if the soil is shallow they will grow laterally. I have had no problems identifying the herb when finding it in the wild because as the name suggests the little leaves of the plant look perforated when held up to the sun.  These perforations are actually oil glands.  Hypericum perforatum flowers appear in the second year and are a bright, golden-yellow with five petals that have very small black dots around the edge. The center of the flower has many yellow stamens that remind me of a sparkler.  If you squeeze the flowers you will get a red stain on your hand due to the hypericin oil.  Tiny, sticky fruit bulbs contain the seeds and due to this sticky medium, they are transported easily by birds and animals.


Cold and dry.


Alterative, alterative, analgesic, anti-convulsant, anti-depressant, anti-inflammatory, anti-depressant, anti-microbial, astringent, diuretic, expectorant, nervine and sedative.


Anxiety, enveloped viruses, excitability, fibrositis, mild depression, nervousness, nervous excitability, nervous exhaustion, neuralgia, menopausal depression, premenstrual syndrome, sciatica, and topically for wounds, nerve pain (which includes headaches and schingles) and.

St John’s Wort is an important plant in herbal medicine and one of my favorite ways of using it is topically by preparing an oil infusion of the fresh flowers. Learn how to make St John’s Wort infused oil yourself, here. Purchase my gorgeous, deep red, St John’s Wort, here. Constituents: Essential oil, flavonoids, Hypericin, Hyperforin, and pseudohypericin.

Contraindications:  Avoid in severe depression, pregnancy and lactation. Do not use when on the following drugs: irinotecan, imatinib, verapamil, HIV drugs, cyclosporin, methadone, anticoagulants, digoxin, theophylline, and the oral contraceptive pill. Avoid with anti-coagulants.  Avoid excessive sun exposure.

Dosage:  Dry herb 4.5-9grams per day 1:2 Liquid extract 20-40mls per week

References: Agriculture Victoria,

Phytotherapy Desk Reference by M. Thomsen and H. Gennat p: 69-70 A Modern Herbal by Mrs. M. Grieve p: 707

The Ultimate Herbal Compendium by Kerry Bone p:64

The Complete Herbal Tutor by Anne McIntyre p:75

Disclaimer: At Byron Botanicals we do not diagnose disease or illness. We offer products or consultations that may assist in your health and lifestyle but only after you have had advice from your doctor or specialist. Should you have any unknown symptoms, speak to your doctor or specialist first. We make no healing claims about the products offered by our website.

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