St. John’s Wort

General Information

Common Name:
St. John’s Wort

Latin Name:

Hypericum perforatium 



Other Names:

  • St. John’s Wort;
  • Goatweed;
  • Hypericum;
  • Klamath Weed;
  • Amber touch-and- heal.

Indications & Historical Uses

St. John’s Wort is one of the most popular herbal remedies for depression. A tea prepared from the leaves and flowering tops of hypericum perforatum L. is widely used in Europe today for its anti depressive effects. It is also used to relieve anxiety and in the treatment of sleep disturbances. It is the most popular non- prescription drug for treating mild to moderate depression. Other possible benefits of St. John’s Wort are relief from menstrual cramps, promotion of wound healing and the fighting off of certain viral infections. Historically, it has been used for the following conditions:

  • Depression and other emotional illnesses;
  • Anxiety;
  • Kidney disorder;
  • Wound and burn healing (Externally);
  • Anti bacterial;
  • Anti viral – AIDS;
  • Bed wetting and childhood night terrors;
  • Gastritis, gastric ulcers and inflammatory bowel disease;
  • Menstrual cramps;
  • Diuretic;
  • Myalgia and neuralgia (Externally);
  • For PMS(premenstrual syndrome).

Contraindications & Precautions

Although, to date, there have been no reports of any serious problems in humans, this herb can be poisonous to cattle. However, prolonged and high dose (1800 mg. per day) consumption of hypericum may render the skin photosensitive especially in individuals who are already sensitive to sunlight. Therefore persons taking St. John’s Wort should avoid excessive exposure to sunlight, tanning lights or UV sources. Also anyone on any prescribed psycho-active medication should consult with their physician before combining it with St. John’s Wort. (See Caution). Topically, St. John’s wort oil is a skin irritant.

Adverse Side Effects:
Photosensitivity causing dermatitis and inflammation of mucus membranes.

Drug Interactions:
Because of its MAO inhibition type of activity, it may potentiate the effects of other MAO inhibitors. However, the MAO 1 activity in St. John’s Wort, in usual doses, is not enough to cause interaction with tyramine containing foods like red wine and cheese.

Secondly St. John’s Wort may cause serotonin syndrome when combined with other drugs which affect serotonin levels. These drugs include:

  • Selective serotonin reuptake inhibitors (SSRI’s);
  • Tricyclic antidepressants;
  • Amphetamine;
  • Mono amine oxidase inhibitors (MAOIs)s;
  • Dopamine agonist such as bromocriptine.

Therefore patients who combine these and other similar products should be advised to contact their physician if they develop any of the symptoms of “Serotonin Syndrome”. Serotonin Syndrome is characterized by sudden onset and rapid progression of some or all of these symptoms:

  • Confusion;
  • Agitation;
  • Shivering;
  • Fever;
  • Diaphoresis (profuse sweating);
  • Diarrhea;
  • Nausea;
  • Myoclonus (muscle spasms or twitching);
  • Hyperreflexia;
  • Tremor.

These reactions can be fatal.

How Supplied:

For internal use:
Capsules, fluid extract, tincture 

For external use:
oil, ointment.


300 mg standardized / three times daily


St. John’s Wort comprises of a number of active ingredients, namely dianthrone derivatives (hypericin and pseudohypericin) flavonoids and tannins (hyperoside, quercitin, rutin, catechin), xanthrones, monoterpenes and sesquisterpenes and phytosterols (beta-sitosterol) Hypericin and xanthones and flavonoids have been shown to have mono-amine oxidase (MAO) inhibiting property. In depression, MAO inhibitors are used to reduce the breakdown of neurotransmitters such as norepinephrine and serotonin and thereby increasing their concentration in the central nervous system. Recent clinical trials using standardized hypericin extract showed improvement in symptoms of depression including anxiety, insomnia, depression and feelings of worthlessness. Most recent research at two of the world’s leading medical institutions, New York University and the Weizman Institute of Science in Israel ,found that 2 of the main constituents of St. John’s Wort namely hypercin and pseudohypericin were found to inhibit the growth of retroviruses (including HIV, the AIDS virus) in animals. Although the results of these studies are promising, more work needs to be done. The mechanism is thought to involve the production of oxygen free radicals which can damage the viral envelope. Therefore, non- enveloped viruses , e.g. Adeno virus or poliovirus are not affected by hypericin. At present, human studies involving high doses of synthetic form of hypericin (10mg) are being tested on HIV infected patients. In addition to its anti depressant and anti-viral properties, St. John’s Wort has significant wound healing properties. St. John’s Wort increases the rate of healing in second and third degree burns. The product used is sometimes known as “red oil”. It is named after the red color formed when the fresh flowers are extracted in olive oil. Increased epithelialization of wounds also occurs when St. John’s Wort is taken orally as an 1:10 tincture. It is likely that some of the wound healing activity of St. John’s Wort may come from anti bacterial activity. Additionally, the flavonoids are tannins and they exert their wound healing effects through their astringent and protein precipitating actions

Active Ingredients:

  • Glycosides (hypericin, pseudohypericin);
  • Flavonoids and tannins.

Standardized extract should contain 0.3 – 0.5% Hypericin

Enhancing Agents:

  • Beta Carotene;
  • Vitamin C.


Hypericum perforatium is an aromatic perennial herb and belongs to the family hypericaceae. It is native to Europe, but is found worldwide. It has golden yellow flowers – flowering between June and September. The flowers have the brightest appearance on June 24th , birthday of John the Baptist.

St.John’s wort is a natural source of food flavoring in Europe. It is also used in pastilles and lozenges and in alcoholic beverages. Active ingredients are extracted from the leaves and the flowering tops.


Processing involves harvesting of the aerial parts of St. John’s Wort, drying away from sunlight and extraction by water and ethanol.

Scientific References

Hobbs, C. (1989) St. John’s Wort. A review Herbal Gram 18/19:24.

Muldner, Von H. and Zoller, M. (1984) Antidepressive activity of an hypericin standardized extract of Hypericum. Arzeneim. Forschh. /Drug. Res. 34:918.

Gerhardt, J.J. and Fowkes, S. W. (1991) Antiviral activity of the photoactive plant pigment hypericin. Photchem. And Photobio. 54(1): 95.

Schinazi, R.F. et al (1988) Therapeutic agents with dramatic anti-retroviral activity and little toxicity at effective doses: aromatic polycyclic diones hypericin and pseudohypericin. Proc. Natl. Acad. Sci. (USA) 85:5230.

Weiner,M. (199)) Weiner’s Herbal. Mill Valley: Quantum Books.

Suzuki, O. et al. (1984) Inhibition of monoamine oxidase by hypericin. Planta medica 50:272.

Pahlow, M.: Duetsche Apotheker Zeitung 42:2059-2060(1984).

Wichtl,M., ed.: Teedrogen, Wissenschaftliche Verlagsgesellschaft, Stuttgart, 1984, pp. 178-180.

Holzl, J., Demisch Apotheker Zeitung 130:367 (1990).

Okpanyi, S.M.and Weischer,M.L.: Arzneimittel-Forshng 37(1):10-13 (1987)

Poginsky, B., Westendorf,J., Prosence, N. Kuppe,M., and Marquardt,H.:Deutsche Aporheker Zeitung 128:1365-1366(1988).

Kommisiion E des Bujndesgesundheitsamtes: Deutsche apotheker Zeitung 128:1499 (1988)

Roth, L.:Hypercium-Hypericin: Botanik, Inhaltssoffe, Wirkung, ecomed, Landsberg/Lech, Germany,1990,pp135-138.

James, J.S.: AIDS Treatment News No. 117:3(1990).

Back To Index

Posted by

Connected Diseases :


General Illness Information Common Name: Depression Medical Term: Major mood or affective disorder Description: Depression is a continuing and persistent feeling of deep sadness, despondency…