Perforate St John s-wort (Hypericum perforatum) is one of the most marketed medicinal plants in the world. Its spread and fame date back to the times of the ancient Greeks and Romans. Its use continued into the Middle Ages and up to the present day, with extracts of H. perforatum being widely used in phytotherapy for the treatment of depressive states or as a skin healing agent. Hypericum is a perennial herbaceous plant native to the British archipelago and now widespread throughout the world. Its complete botanical name is Hypericum perforatum due fact that the leaves appear full of holes when viewed against the light, indeed as if they were perforated. In reality, these are small oily blisters. The popular name of hypericum is, in fact, St. John s Wort, but also scacciadiavoli grass (Italian - literally devil s banishment ) because in the past it was believed that sleeping near hypericum plants would drive away evil spirits and protect against death for at least a year. Probably the reference to St. John s derives from its flowering period which occurs at the end of June (St. John is celebrated on June 24th). This plant grows in open woodland, enjoys exposure to sunlight and resists cold. In some parts of the world, it is considered a weed, while in Europe it is employed for its antiviral and antidepressant properties. The therapeutic properties of hypericum buds are due to the phytocomplex mostly composed of flavonoids, such as hypericin, rutin, quercetin and hyperoside; together with other substances which have marked antidepressant and sedative actions, these are found in plant dry extract or mother tincture. Today, hypericum is mostly known as a powerful serotonergic and therefore a natural antidepressant, expressly indicated for the treatment of depressive states accompanied by emotional anxiety, with agitation, panic attacks, gastrointestinal disorders and insomnia. Its active substance hypericin, in particular, inhibits two enzymes which suppress various mediators of the central nervous system (serotonin, dopamine, noradrenaline) and increases the nocturnal secretion of melatonin, thus countering insomnia. It is also capable of increasing serum serotonin levels and thus rebalancing mood, such as during menopause, in seasonal depression and during periods of severe fatigue or even states of nervous breakdown. Further benefits include inducing a feeling of well-being, reducing states of anxiety or distress and aiding more restful sleep, it also modulates the secretion of melatonin. Hypericum also has immunostimulant, anti-inflammatory, antibiotic, antiviral, anti-fungal, antiseptic and painkilling properties that make it an excellent remedy in all cases of neurovegetative dystonia, gastritis, gastro-duodenal ulcers and chronic neuralgia. Several pharmacological and clinical studies carried out on hypericum have demonstrated its safety as a herbal medicine, but some contraindications should be borne in mind. Hypericum does interfere with the action of a number of drugs, enhancing or inhibiting their effects. Its use is therefore not recommended in the presence of other therapies since it can stimulate certain enzymes that metabolise drugs and thus reduce their circulation. Its action also tends to have a cumulative effect with that of serotonergic drugs. Indeed, clinical studies have shown that taking this medicinal herb reduces the blood circulation levels of drugs such as digoxin (a substance belonging to the category of digitalis glycosides, used to treat a number of cardiac disorders) and can also reduce the effect of Warfarin (a well-known anticoagulant drug). Hypericum weakens the anticoagulant effect of Warfarin and reduces blood levels of Cyclosporine, used to prevent transplant rejection. It is also known to reduce the effect of oral contraceptives. Beware of photosensitivity and avoid exposure to sunlight and/or the use of sunbeds if you are taking hypericum, especially if you have very sensitive and delicate skin.