Extracted from the flowers and leaves of the plant Hypericum Perforatum, St John’s Wort is best known for its antidepressant properties.

What are its health benefits?

Uses of St John’s Wort include treating mild depression and anxiety, emotional disorders like obsessive-compulsive disorder (OCD), menopausal mood swings and premenstrual syndrome (PMS).

Possible antiviral effects of St John’s Wort are also being investigated for the treatment of HIV/AIDS, hepatitis C and other viral illnesses. It is also used to treat coughs and sinus infections, and ease sore muscles.

St John’s Wort is available as a tea, tincture, decoction, an oil, or in tablet or capsule form.

How does it treat depression?

Research has shown that St John’s Wort extract alters brain chemistry by inhibiting the breakdown of several neurotransmitters, including serotonin, dopamine and noradrenalin. This results in an increase in the level of neurotransmitters responsible for mood and emotional stability in the brain.

When should it be avoided?

While St John’s Wort is popular and can be bought over the counter from chemists and health shops, it should be regarded as a drug as it contains pharmacologically active agents.

Avoid during pregnancy and while breastfeeding. It should also not be taken together with the contraceptive pill or anti-epilepsy treatments, if you’re having chemotherapy, or taking certain medications, including antidepressants.

If you’re on any medication, consult your Clicks pharmacist or your doctor before taking St John’s Wort.

Some countries have banned the use of St John’s Wort, because of its interaction with certain medications, while others are in the process of including drug-herb interaction warnings.

Recommended dietary allowance (RDA)

The usual dosage is 350mg twice a day.

Know the overdose risks

Side effects of St John’s Wort include:

  • Sun sensitivity
  • Stomach upset
  • Allergic reactions
  • Anxiety
  • Headache
  • Muscle cramps
  • Sweating
  • Weakness
  • Dry mouth
  • Skin irritation
  • Altered menstrual flow
  • Mania or psychosis
  • A change in the way sugar is processed in the body
  • A stimulation in the release of certain hormones, among others.

Ensure you first discuss taking St John’s Wort with your Clicks pharmacist to avoid the potential for side effects and adverse interactions with medications.

The accuracy of this information was checked and approved by Clicks' pharmacist Waheed Abdurahman in February 2015