St John’s Wort

St John’s Wort wild in Herefordshire, 2018.

St John’s Wort wild in Herefordshire, 2018.

Latin: Hypericum perforatum L.

Botanical Description:

  • Commonly found herbaceous perennial growing up to about 1m tall.

  • Shoots erect and branching on the upper parts.

  • Leaves pale green, sessile and oblong linear, 1-2cm long and covered in translucent oil ducts creating a perforated appearance, hence name perforatum.

  • Bright yellow flowers with 5 petals appear June – August.

Parts used: Herb.

Constituents:

  • Hypericins.

  • Hyperforins.

  • Flavonoids.

  • Tannins.

  • Essential oil – used topically.

Harvesting wild St John’s Wort in Herefordshire, 2018.

Harvesting wild St John’s Wort in Herefordshire, 2018.

Actions:

  • Anxiolytic, sedative.

  • Anti inflammatory, astringent.

Uses:

  • Widely used for mild to moderate depression – supported by many clinical trials.

  • Effect on neurotransmitters – serotonin, noradrenaline and dopamine.

  • Psychological issues associated with menopause.

Safety:

  • Contraindicated with oral contraceptives, cyclosporins and protease inhibitors.

  • May cause photosensitivity in some.

  • GSL.