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]

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.

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.

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.