Do you know why St. John’s wort is called so? This is because this plant traditionally flowers by and is harvested on St John’s day, that is, 24 June. Its other names are Klamath weed and Goat weed (1). This herb had been in use since antiquity for treating a range of diseases and disorders.

St. John’s wort plant

St. John’s wort (Hypericum perforatum) is a flowering shrub, known for its yellow flowers. This plant had been traditionally hung over a picture in the house during St. John’s day to ward off evil. In fact, the genus name Hypericum is Greek for ‘above’ (hyper) and ‘picture’ (eikon)! (2)

Medicinal properties of St. John’s wort

St. John’s wort has anti-inflammatory, astringent and antiseptic properties and its use dates back to ancient Greeks and Native Americans. Historically, the plant was used in herbal tea, which had many curative properties.

In modern medicine, St. John’s wort is used for treating depression and anxiety disorders. This herb has been found more effective in treating mild depression, as compared to over-the-counter antidepressant medication. In most drugstores, standardized extracts are available usually in the form of tablets/capsules and tinctures. They are also available in teabags.

In the preparation of teas and tablets, only the flowering tops of St. John’s wort are used, since they contain concentrated extracts. Its use in homeopathy for various medical problems is also well known, but the success rate has not been adequately documented.

Dosage for St. John’s wort

British Herbal Medicine Association Scientific Committee (1983) recommends the following dosage for various forms of St John’s wort (2):

a. 2 to 4 gram dried herb or by infusion 3 times a day.

b. 2 to 4 ml liquid extract 3 times a day.

c. 2 to 4 ml tincture 3 times day.

However, this dosage is for adults and should not be given to children without consulting the physician, as the dosage varies from child to child.

Effectiveness of St. John’s wort

Studies conducted for the effectiveness of St. John’s wort in treating clinical depression showed mixed results. The good news is this herb was found effective in treating mild to moderate depression, with fewer side effects than many conventional antidepressants (2). However, the bad news is studies sponsored by NCCAM showed that the herb was no more effective than placebo in treating major depression of moderate severity. The research is continuing that encompasses a wider spectrum of mood disorders, including minor depression (2).

Side effects of St. John’s wort

There are certain side effects associated with the use of St. John’s wort. Let’s see what they are (1):

a. Its use may cause increased sensitivity to sunlight. This can also cause sunburns, but the incidence is rare (2).

b. It can cause anxiety, dryness of mouth, dizziness, gastrointestinal symptoms, fatigue, headache, confusion, sedation and even sexual dysfunction.

c. This herb is also known to interact with some drugs. When combined with certain antidepressants, St. John’s wort may increase the incidence of nausea, anxiety, headache and confusion.

d. It may hinder in the efficient processing or breaking down of many drugs. In some cases, it may even speed up or slow down a drug’s breakdown. The drugs that are commonly affected by the intake of St. John’s wort are those for controlling HIV infection, treating cancer, strengthening heart muscle contractions and some anticoagulants and antidepressants.

e. This herb is known to have negative effects on fertility in both men and women (2).

f. Sudden discontinuance of this herb has been found to be quite unpleasant in certain cases (2).

St. John’s wort is an effective herb, but should be used judiciously. The best course is to go by the recommendations of your physician, in case you’re using any medicine or dietary supplement containing St. John’s wort.

References

1-http://nccam.nih.gov/health/stjohnswort/
2- http://en.wikipedia.org/wiki/St._John’s_Wort