St Mary’s Thistle, sometimes referred to as Milk Thistle, is considered a weed in Australia , however in Herbal Medicine it is seen as one of the primary liver tonic herbs available. It has a history of use that appears to date back 2,000 years for conditions that affect the liver and biliary systems. St Mary’s Thistle contains a constituent called silymarin that has been found to play a large part in the therapeutic actions of the herb. The herb’s actions have been identified as hepatotonic, anti-oxidant and choleretic. It can provide support to the liver, as well as assist the release of bile from the liver and gall bladder.