translated from a website in French




Hypericum is a botanical genus that includes several hundred herbaceous or shrub species (more than 400) widespread in all temperate regions, Asia, Europe and the Americas.
Some species of Hypericum have been introduced to Australia where they are considered invasive.

Hypericum perforatum, the true St. John's Wort, is a small herbaceous perennial, 20 to 90 cm, very common in Europe, found in sunny and dry places: uncultivated land, fallow land, roadsides.

The stalk of St. John's wort is reddish, the leaves oval, sessile and opposite, giving the appearance of being riddled with small holes.

These are actually small glandular organs, more or less transparent, which contain an essential oil.

There are black punctuations on the lower faces of the leaves.

When one crumples the leaves between his fingers, they are stained in red.

The flowers of St. John's wort, in terminal cymes, are pentameric, bright yellow (punctuated with black), turning to rust when they fade.
The stamens, numerous, are gathered in 3 bundles. The fruit of Hypericum perforatum is a capsule that opens in three parts.
St. John's wort, Hypericum perforatum, is in full bloom in early summer, it is the herb of St. John (24 of June).

Hypericum perforatum easily hybridises with neighboring species (barbatum, maculatum, montanum, etc.) so we often encounter intermediate types of St. John's Wort.



St. John's Wort contains:

• Compounds found in many plants: 4 to 5% flavonoids (rutin, quercetin, kaemferol, luteolin), carotenoids, a lot of tannins (10% of the dry weight).

• Other pharmacologically interesting phenolic compounds: chlorogenic acid and other phenolic acids, phloroglucinol derivatives (including hyperforin), xanthones .

• 0.1% essential oil (pinene, sesquiterpene carbides)

• Naphthodianthrones which are characteristic of this plant; they are condensed and oxygenated aromatic molecules (quinone) responsible for the reddish coloring that appears when the leaves are creased: hypericin, pseudohypericin and related compounds.

Hypericin is a naturally powerful, photo-sensitizing substance. According to chemists, it absorbs visible and UV radiation and becomes phototoxic by releasing very reactive free radicals (singlet oxygen); I quote: "there is a photo-induced proton transfer from the first triplet state".
In practice: applying reddish "juice" of Hypericum perforatum to thin skin or eroded skin and exposing it to the sun may cause erythema (redness and pain ), even phlyctenes and micronecroses.

The phototoxic power of St. John's wort induces sometimes serious disorders in herbivores that absorb large amounts of it.

Hypericin is antiviral, active against "encapsulated" viruses, examples: herpes, hepatitis B, cytomegalovirus, viruses causing "flu-like" respiratory infections, retroviruses (including the AIDS virus (HIV)) and many others virus.
The antiviral potency of hypericin has been studied in vitro and in animals; the tests in humans (AIDS) have been abandoned (to my knowledge).

Pharmacologists cannot determine exactly which substances are responsible for the pharmacological properties of Hypericum perforatum, St. John's Wort.

Hypericum perforatum has indeed a lot of interesting properties:

• Mood modifier: sedative, anxiolytic, antidepressant .

• Anti-inflammatory (flavonoids + essential oil) .

• Antibacterial and antiviral (flavonoids including hyperforin and hypericin).

• Antiseptic, astringent and healing (flavonoids and tannins).

• Analgesic.

• Regulator of liver function (activation of certain enzymes: enzymes of the cytochrome P450 complex) and gastric.

• Balsamic respiratory stimulant

Hypericum perforatum, St. John's wort, mood regulator,
anxiolytic and antidepressant

St. John's Wort, Hypericum, is best known today as an anti-depressant and calming medicinal plant.

For fifteen years there have been many studies on the antidepressant power of Hypericum.

The results are irregular, even contradictory, but the studies are often biased. Indeed, the sponsors of these investigations are generally laboratories, "pro or anti-hypericum", involved in the trade of psychotropic drugs.

The most recent and independent results confirm the antidepressant properties of Hypericum extracts in humans in mild to moderate depression.

These studies also show the interest of St. John's wort in fighting insomnia and improving the quality of sleep. For a long time pharmacologists considered Hypericum extracts as monoamine oxidase inhibitors (MAOIs), but now they are more inclined to think that they inhibit neurotransmitter absorption at neuronal synapses: serotonin, norepinephrine and dopamine.

The very important role of serotonin in regulating mood is well known.


St. John's wort, Hypericum is used :

• In infusion of the fresh or dry plant: 100 g to 150 g of fresh plant or 25 to 50 g of dry plant in a liter of water.
This rather astringent infusion can constipate.

• Infused in the oil: 500 g of Hypericum, in a liter of vegetable oil (olive for example), put in the sun for several days or warm gently for 2-3 hours, filter and keep away from light in a well clogged container.

• In ethanolic tincture (1/10) if possible with fresh plant(homeopathic tincture).

• In fluid extract .

• As a plant powder.

Commercially available proprietary medicinal products containing St. John's wort or St. John's Wort extracts are commercially available in pharmacy or on internet

Depression, Obsessive Compulsive Disorder

Example of dosage:

Hypericum perforatum: etanolic tincture (1/10) if possible of fresh plant, 50 drops 3 times a day .

Hypericum perforatum: capsules or drops, standardized extracts in Hypericin (0.3%, or 250 to 500 µg of total hypericin per capsule) or hyperforin ( 1 to 3%): 300 to 400 mg of standardized extracts 2 to 3 times a day or standardized capsules, 2 to 3 times a day

Sleep disorders, Smoking cessation

Example of dosage :

• Standardized Hypericine or Hyperforin Drugs: 200 to 300 mg of Hypericum Extract .

• Hypericum powder: 1g, two capsules per day.

• Ethanolic tincture of Hypericum: 30 drops 3 times a day or 50 drops at night .

• Infusion of St. John's Wort: 2 to 4 cups a day

Painful sores(hand and fingers), second-degree burns, infected and painful wounds

These indications are more traditional . You can use St. John's wort infusion decoction or St. John's Wort oil. Recent studies have shown St. John's wort to be active on antibiotic-resistant staphylococci strains and promote healing. The treated part must be protected from the sun's rays.

Neuralgic pain

This indication of St. John's Wort oil is quite old. It is applied in massage on the painful regions or on the bottom of the spine and along the sciatic nerve in case of chronic pain.


Recent work has investigated the possibility of using concentrated hypericin followed by exposure to intense light, to eliminate dyskeratosis, basal cell cancers of the skin and even some melanomas difficult to operate.


St. John's wort, Hypericum perforatum, has not been recommended for use by children, pregnant women, or breastfeeding women, although recent studies on too few subjects have shown no problems in pregnant or breastfeeding women.

St. John's wort extracts increase the activity of certain liver enzymes that have the mission to detoxify the body, but also accelerate the degradation of many molecules, including some important drugs.

• protease inhibitors and reverse transcriptase inhibitors (AIDS treatment);
• cyclosporine (immune inhibitor used in the prevention of graft rejection);
• antivitamin K (anticoagulant treatment);
• certain drugs used in the treatment of cancer; and to a lesser extent
• certain antibiotics;
• statins (anticholesterol);
• anticontraceptive pill and other hormones (estrogen and cortisol);
• theophylline (treatment of the asthma attack).
• digoxin (heart failure) also sees its metabolism altered, perhaps by a change in its intestinal absorption

The majority of people can therefore use St. John's wort (recall: except those who use antiretrovirals, ciclosporin, anticoagulant therapy, or digitalis)
St. John's wort extracts interact with synthetic antidepressants ("Prozac" type, MAOI or tricyclic) it is necessary to pass smoothly from one treatment to another.

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Hypericum perforatum, St. John's Wort, is a small, common plant in temperate countries around the world. It contains hypericin, a photosensitizing substance. St. John's wort extracts help treat mild or moderate depression, mild anxiety and insomnia. St. John's wort extracts are contraindicated in some people including AIDS patients and transplant recipients.