Milk thistle

Silybum marianum

Also: Mary's thistle, Holy thistle, St Mary's thistle

CoolingMoisteningRelaxing

Protects and rebuilds a hardworking liver.

A bold thistle with glossy leaves marbled in milky white veins and spiny purple flower heads that ripen into shiny, oily seeds. Milk thistle shields liver cells from damage, helps them regenerate, and cools inflammation, so gently that it suits almost anyone whose liver is under strain.

Energetics: Cooling, moistening, relaxing
Taste: Nutty, salty, sweet
Family: Asteraceae (daisy family)
Parts used: Seed

Medicinal uses 3

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Traditional useLab and mechanism studiesClinical studies

Sluggish liver & digestionTLC
Protects and helps regenerate liver cells, for anyone whose liver carries a heavy load from medicines, alcohol, stress, or illness.
Blood sugar balanceTLC
Lowered fasting blood sugar and HbA1c in trials of people with type 2 diabetes.
Acne & breakoutsTLC
Supports the liver's handling of hormones in skin that breaks out with the cycle.

Preparations

Freshly ground seed on food, capsules, and tincture. Tea pulls out very little.

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Cautions

Very safe. High doses can loosen the stools.
People allergic to ragweed or daisies can react to it.
Silymarin barely dissolves in water, so tea is a weak way to take it.

Medication interactions

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Pregnancy & breastfeeding

PregnancyWith your midwife

Pregnancy data are limited. Midwives and doctors sometimes use it for liver problems in late pregnancy under supervision.

BreastfeedingGenerally compatible

A traditional milk-supply herb with a reassuring safety record.

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Folklore

Silybum marianum honors the Virgin Mary; legend says a drop of her milk fell on the leaves and left the white veins. Greek and Roman physicians gave it for complaints of bile, and in modern Europe an injectable extract of its silibinin is used as an antidote to death cap mushroom poisoning.

How to grow

An easy annual or biennial for full sun and poor, dry soil, and a weed in some regions, so deadhead it. Wear gloves. Snip seed heads as the white fluff appears, dry them in a paper bag, and rub out the seed.

In the wild

Native to the Mediterranean and now wild in dry pastures and roadsides of California, Australia, and South America.

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