St John's Wort Overview

(Hypericum perforatum)

St John's Wort is a species of plant traditionally known for its antidepressive and anti anxiety properties.

Indigenous to Europe, St John's Wort plant is a wild growing shrub like herb, introduced to, and now found in many temperature areas across the globe.

Although a herb, St John's Wort is often classed as a weed. This herb is invasive in nature and being perennial, flowers each year.

Properties Of St John's Wort

St John's wort is a relatively short plant, growing to a height of about 1 meter.

The plants flowers are yellow and the leaves contain what look to be tiny holes through which light can shine through. These are not holes but small translucent oil glands.

When preparing the plant for medicinal use, the seeds and flowers are crushed to produce a dark red to purple colored liquid. When one of the various types of St John's wort herbal preparations are taken by people, a variety of therapeutic benefits may be experienced.

Taking St John's Wort is generally considered safe but may bring mild and limited side effects. However, under certain circumstances there may be dangers when taking St John's wort, which a person taking this herb should consider.

In contrast to humans who tend to tolerate this herbal plant, St John's Wort can be poisonous to animals such as livestock. St John's Wort can cause severe health problems to livestock when they graze on this plant.

When consumed in sufficient quantities, complications such as central nervous system (CNS) depression, photosensitization, spontaneous abortion, and even death can arise.

Fortunately these complications don't arise in humans although photosensitization, a rare side effect of St John's wort, can occur (see also dangers of St John's wort).

Where Does The Name St John's Wort Come From?

The flowers of St John's wort typically bloom around mid summer in Europe from where this herb is indigenous to. It is around this time St John's wort is harvested. As St John's Day falls on 24th June midsummer day, the plant is named after St John the Baptist.

The second part of the name, 'wort', is a traditional old English name for plant.

St John's wort is a plant of historical significance; records referring to this plant date back more than 2000 years to ancient Greece. Throughout history, many different names have been given to St John's wort (Latin name: Hypericum perforatum).

St John's wort is also known as:

  • Amber
  • Hardhay
  • Hypericum
  • Goat weed
  • John's wort
  • Klamath weed
  • Lungwort
  • Rosin Rose
  • Soapwort
  • St Johns wort weed
  • Tipton weed
  • Touch-and-heal
  • Woundwort

Chemical Properties Of St John's Wort

Chemically, St John's wort is a complex plant. St John's wort contains many different chemical compounds and their interactions are not completely understood.

St John's wort extracts include:

  • hypericin
  • hyperforin
  • flavonoids
  • xanthones
  • tannins

Hypericin and hyperforin are linked to the antiviral and antidepressive benefits of St John's wort. Other ingredients, including flavonoids, xanthones and tannins, may also have a medicinal effect.

For example, tannins are known to help soothe the skin (see also, 'benefits of St John's wort').

Despite being used throughout history, compared to traditional antidepressant medication, there is less research into the use of this herb as an antidepressant (and other conditions).

There is also debate as to which extract, or combinations of extracts are responsible for the various health benefits of St John's wort. For example, it was thought that hypericin was the active ingredient behind the plants antidepressant properties.

However, there is more recent research suggesting that another active ingredient, hyperforin, is linked to these properties.