St. Marys Thistle has been approved for registration as a regular medicine in Belgium. The hepatotropic properties of this plant are rather difficult to evaluate objectively. Mortality rate in case of life-threatening hepatic diseases is the most objective parameter. Legalon is the only drug registered in Belgium. It has a prescription only status. The plant Silybum marianum is a thistle and as a consequence belongs to the Compositae. There is a limited production of St.-Marys Thistle in Pajottenland, west of Brussels. The seeds are exported to Italy in order to extract silymarine, a mixture of flavonolignanes with antioxidant properties. Silymarine has been tested in living animals deliberately intoxicated with mushroom toxins, medicines, heavy metals or toxic organic solvents. Preventive as well as curative activity has been confirmed. Silymarine accumulates in the liver, which is also the target organ in therapy. Silymarine improves the prognosis after accidental ingestion of the toxic Amanita phalloides. Patients infected with hepatitis B and C might benefit from Silymarine, but more data have to be generated. Silymarine given to patients with liver damages by alcohol lowers the death toll. The drug has a general safety pattern comparable to placebo.