St. John's Wort

Also called

Klamath Weed, Tipton Weed, Goatweed

Traditional names

Guan Ye Lian Qiao (贯叶连翘)

Older scientific names

Hypericum officinale Gaterau, Hypericum officinarum Crantz, Hypericum vulgare Lam.

Traditional use

These are traditional uses, not proven treatments.

• St. John's wort has been widely used in Greek, Islamic and Chinese medicine. Historically, it has been used for depression, stomach ulcers, colds and wound healing.[4]Health agency

• In Islamic traditional medicine, it was used for infected wounds, burns and bruises; to increase urination; to bring on menstruation; to lower fever; and for sciatica (nerve pain down the leg). In Traditional Chinese Medicine (as Guan Ye Lian Qiao), it was used for vomiting or coughing up blood, bleeding between periods, irregular periods, bleeding from injuries and wound care.[3]Study

  Technical detail: diuretic, emmenagogue, antipyretic; hematemesis, hemoptysis, metrorrhagia, traumatic hemorrhage.

Laboratory & animal research

Lab and animal results show what might be worth studying in people. They don't show that the herb has these effects in humans.

• This research explains St. John's wort's drug interactions. A compound in the plant called hyperforin switches on a sensor in the body that speeds up the liver enzymes and "pump" proteins that clear many medicines out of the body. The more hyperforin a product has, the stronger this effect. Low-hyperforin extracts showed little effect.[3]Study

  Technical detail: hyperforin activates the pregnane X receptor (PXR), inducing CYP3A4, CYP2C19, CYP2C9, CYP1A2 and CYP2D6, and the efflux transporter P-glycoprotein (P-gp/ABCB1); CYP3A4 induction correlates with hyperforin content.

Research in people

• A 2008 Cochrane review pooled 29 high-quality trials with 5,489 people with major depression. The extracts tested worked better than placebo (a dummy pill), about as well as standard antidepressants, and caused fewer side effects. But trials from German-speaking countries were much more positive than trials elsewhere, which makes the results harder to interpret. The findings only apply to the specific extracts tested, and products on the shelf vary a lot in quality.[6]Review or trial

  Technical detail: randomized, double-blind trials of hypericum extracts.

• Individual trials have had mixed results:

  • 2011, 12 weeks, minor depression: neither St. John's wort nor the antidepressant citalopram did better than placebo.
  • 2012, 26 weeks, moderate major depression: St. John's wort, the antidepressant sertraline and placebo all worked about equally.
  • 2002, moderate major depression: St. John's wort did no better than placebo.

  A 2008 review concluded it may be better than placebo, and as effective as standard antidepressants, for mild to moderate major depression.[5]Health agency

• St. John's wort may help mild or moderate depression, and seems about as effective as standard antidepressants over periods of up to 12 weeks. It's unclear whether it helps severe depression or works beyond 12 weeks. Limited evidence suggests it might help menopausal hot flashes and somatic symptom disorder (intense distress about physical symptoms). There is little research support for ADHD, irritable bowel syndrome, obsessive-compulsive disorder, PMS, quitting smoking or healing wounds on the skin.[4]Health agency

• Used on the skin, a St. John's wort cream standardised to 1.5% hyperforin improved the skin and reduced Staphylococcus aureus bacteria on it in people with mild to moderate atopic dermatitis (eczema), clearly better than a dummy cream, according to a 2013 review. An oil made by soaking the flowering tops in vegetable oil is traditionally used on minor cuts, burns and skin ulcers.[7]Study