St John's wort

Hypericum perforatum

Also: Hypericum, Solsticewort, Klamath weed

WarmingDryingRelaxing

Midsummer sunshine for nerves, gut, and grey moods.

Bright yellow, star-shaped flowers whose buds bleed red when pinched, and leaves pricked with tiny translucent dots. St John's wort restores damaged nerves, heals wounds, and lifts depression that travels with a sluggish gut and liver.

Energetics: Warming, drying, relaxing
Taste: Bitter, aromatic, astringent
Family: Hypericaceae (St John's wort family)
Parts used: Flowering tops

Medicinal uses 6

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Traditional useLab and mechanism studiesClinical studies

Low moodTLC
Lifts mild to moderate depression, particularly alongside poor digestion and seasonal greyness.
Nerve painTLC
The red oil, rubbed in over weeks, restores injured nerves and eases sciatica and neuralgia.
Cuts, scrapes & bleedingTLC
Speeds wound healing and softens scarring.
Bruises & sore musclesTLC
The infused oil soothes bruises and sore, overworked muscles.
Cold soresTLC
Active against herpes-family viruses.
Muscle tension & spasmTLC
The red infused oil, rubbed along the spine and shoulders, eases sore, tight muscles.

Preparations

Sun-infused red oil, a bitter tea, and fresh-plant tincture.

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Cautions

Taken internally, it speeds the liver's clearance of many medications, including birth control pills, antidepressants, blood thinners, thyroid hormone, HIV medications, and transplant drugs. Avoid it alongside any medication unless your prescriber confirms it is safe.
Concentrated supplements can cause sun sensitivity.
The topical oil is safe regardless of medications.

Medication interactions

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Pregnancy & breastfeeding

PregnancyAvoid

Drug interactions, newborn withdrawal-like symptoms, and a higher preterm birth rate in one study put it off the list in pregnancy.

BreastfeedingAvoid

Drowsiness, colic, and poor feeding have been reported in nursing babies, along with reduced milk supply.

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Folklore

It blooms around the summer solstice and the feast of St John the Baptist on June 24, and people gathered it on Midsummer Eve to hang over doors and windows against evil spirits, which earned it the name fuga daemonum, devil's flight. The red pigment that bleeds from its buds was read as the saint's blood, and the pinpricks in its leaves as the devil's stabs. In the American West it became Klamath weed, poisoning sheep and cattle, until California released leaf beetles in the 1940s in one of the first successful biological controls of a weed.

How to grow

A hardy perennial for full sun and dry, poor soil, easy from surface-sown seed. Harvest the top few inches at peak bloom, buds and open flowers together. Check local weed lists first; it is restricted in parts of the US and Australia.

In the wild

Native to Europe and western Asia, now naturalized and often invasive along roadsides, rangeland, and clearings across North America, Australia, and beyond.

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