Milk Thistle

    Researchedby:
    Daryl Nault, Giulia Guerrini

    Fact-checked

    by:

    Nick Milazzo
    Last Updated: February 26, 2024

    Milk thistle (Silybum marianum) contains silymarin, a complex of plant compounds known for their hepatoprotective (liver-protecting) properties.

    What is milk thistle?

    Milk thistle (Silybum marianum) is a medicinal plant belonging to the Asteraceae/Compositae family. It is native to Southern Europe, Central Asia, and Ethiopia[3] and grows particularly well on the sunny slopes of the Mediterranean countries. Milk thistle’s leaves have characteristic white, “milky” veins, and the plant can grow up to 6 feet tall. It typically blooms from June to August, after which its black seeds are harvested to be used for medicinal purposes. Milk thistle can now be found throughout California, South America, Africa, Australia, and Asia.[4][1]

    Although the terms milk thistle and silymarin are often used interchangeably, silymarin is a complex extracted from the dried seeds and fruits of milk thistle.[4][5][6] Milk thistle extracts are typically odorless and contain 70–80% of silymarin.[7]

    What are milk thistle’s historical uses?

    What are milk thistle’s main benefits?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s main benefits.

    What are milk thistle’s main drawbacks?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s main drawbacks.

    How does milk thistle work?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s mechanisms of action.

    What are other names for Milk Thistle?

    Note that Milk Thistle is also known as:

    • Marian thistle
    • Mary thistle
    • St Mary’s thistle
    • Our Lady’s thistle
    • Holy thistle
    • Sow thistle
    • Blessed Virgin thistle
    • Christ’s crown
    • Venue thistle
    • Heal thistle
    • Variegated Thistle
    • Wild Artichoke
    • Carduus Marianus
    • Silybum marianum

    Milk Thistle should not be confused with:

    Dosage information

    Milk thistle supplements are sold in the form of capsules, tablets, and tinctures and also exist as intravenous solutions (only available in hospital settings).

    The recommended daily dosage of any given milk thistle supplement depends on both the treatment purpose and the supplement’s silymarin content.

    When silymarin is used for hepatoprotection, the recommended daily dosage typically falls in the range of 420 mg to 600 mg of silymarin per day, usually taken in three split doses.[1][2]

    Frequently asked questions

    What is milk thistle?

    Milk thistle (Silybum marianum) is a medicinal plant belonging to the Asteraceae/Compositae family. It is native to Southern Europe, Central Asia, and Ethiopia[3] and grows particularly well on the sunny slopes of the Mediterranean countries. Milk thistle’s leaves have characteristic white, “milky” veins, and the plant can grow up to 6 feet tall. It typically blooms from June to August, after which its black seeds are harvested to be used for medicinal purposes. Milk thistle can now be found throughout California, South America, Africa, Australia, and Asia.[4][1]

    Although the terms milk thistle and silymarin are often used interchangeably, silymarin is a complex extracted from the dried seeds and fruits of milk thistle.[4][5][6] Milk thistle extracts are typically odorless and contain 70–80% of silymarin.[7]

    What are milk thistle’s historical uses?

    Milk thistle has a rich history of medicinal use dating back to ancient times. The physician and pharmacologist Dioscorides (40–90 AD) was among the first to report using milk thistle to treat serpent bites. Pliny the Elder (23–79 AD) also documented its use for removing bile when milk thistle was mixed with honey.[5]

    During the Middle Ages, milk thistle gained a reputation for having positive effects on liver health and as an antidote for liver toxins. This perspective persisted through various historical periods, with figures like the British herbalist Culpepper recommending it for liver obstructions. Physicians Felter and Lloyd also noted its potential benefits for liver "congestion." Today, milk thistle remains a popular supplement widely used by healthcare practitioners.[5]

    What are milk thistle’s main benefits?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s main benefits.

    What are milk thistle’s main drawbacks?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s main drawbacks.

    How does milk thistle work?

    Research on milk thistle is primarily focused on its main bioactive extract, silymarin. Please refer to the silymarin page for a description of silymarin’s mechanisms of action.

    Update History