St Mary’s Thistle

Silybum marianum

An annual to biennial herb that grows to 35-125cm (1-4ft), in height. The leaves are dark green, oblong with spiny margins that give them a mottled appearance. The spiny flowers are deep violet in colour, approximately 1-2cm (half inch) in diameter and sit above rows of spiny bracts. The fruit is 6-7mm, wrinkled with a yellow ring near the apex.

Family: Asteraceae

Which probiotic is it in?: St. Mary’s thistle is a key herb in Bio-Live Liver.

Habit and cultivation: Native to the Mediterranean it now is widespread throughout the world. Growing wild and thriving on waste lands, it is also cultivated as an ornamental dried flower. Likes a sunny position, in a well drained soil. Easy to grow and matures in less than a year.

Actions (known for): Hepatoprotective, anti-oxidant, galactogogue, demulcent, cholagogue and digestive tonic.


The use of Silybum goes back 2,000 years; it was traditionally used to increase breast milk production, treat depression (traditionally associated with the liver), eaten as a vegetable (the flower heads boiled and eaten like artichokes) when there were no fresh ones available after winter. Culpepper recommended boiling the leaves as a blood cleanser. Traditionally the milk white veins of the leaves were found originally in the milk of the Virgin Mary, who fell upon a thistle plant. The Saxons also believed that if the seeds were worn around the neck, snakes would not come near.

Parts used:


Constituents (bio available chemicals):

Flavanolignans including; silybin, silychristin, silydianin that are collectively known as silymarin. Flavonoid – silymarine. Bitter principle. Amines including tyramine and histamine. Polyacetylenes.

Nutritional constituents:


Liver tonic, chronic liver and gallbladder disorders such as cirrhosis, damage from chemical poisoning and alcohol abuse, cholangitis, pericholangitis, gall stones, chronic hepatitis (including B and C), as a supportive during acute hepatitis. Stimulates the flow of breast milk. Externally: can be used for psoriasis, eczema, burns, wounds and sores.


Seeds: 4-9g daily. Liquid extract (1:2): 30-60ml per week. Absorption of silybum is enhanced by lecithin.

British Herbal Pharmacopoeia

Cautions for therapeutic doses

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