Milk thistle supplements are made from silybum marianum, a plant that has been used historically to treat liver and gall bladder disorders. It's also known as holy thistle, Marian thistle, Mary thistle, Our Lady’s thistle, St. Mary thistle, and wild artichoke. It may help to reduce elevated ALT levels, however, you must speak with your doctor before taking milk thistle supplements.
Sylimarin is believed to be the active compound of milk thistle that affects the liver. According to the National Cancer Institute, laboratory studies show sylimarin stabilizes cell membranes, which prevents the entry of toxins, and functions as an antioxidant. It also stimulates the glutathione S-transferase pathway and increases the amount of glutathione in cells. Glutathione is a metabolic enzyme that works as an antioxidant and reduces the effect of some toxic substances in the body.
Alanine Amino Transferase
Alanine Amino Transferase, also known as ALT, is a blood test used to determine liver damage. Blood levels of ALT increase with chronic liver diseases such as cirrhosis and hepatitis. It can also be used to monitor treatment of liver diseases because levels will come closer to normal levels when treatment is successful. "Natural Standard," a peer-reviewed alternative medicine collaboration, states sylimarin has been shown to lower ALT levels in research studies, but not all of the studies were of good quality.
Chronic liver diseases include fibrosis of the liver, which can progress into cirrhosis of the liver, according to the University of Maryland Medical Center. These diseases cause scar tissue to replace normal tissue, which reduces blood flow through the liver. This damage reduces your liver's ability to process drugs, nutrients and toxins. Hepatitis is an inflammation of the liver and can be due to excessive drug or alcohol use, viral infection or due to immune system dysfunction.
Milk thistle supplements are considered safe according to "Natural Standard," however they may interact with certain medications, and in extremely large doses, may have a laxative effect and may increase ALT levels. Dietary supplements are not regulated for effectiveness by the U.S. FDA, so do not take milk thistle supplements before talking to your doctor.