Alternative names: Milk thistle.
The use of Silymarin is just beginning to be explored in the United States. Without doubt, this will be one of the leading botanical ingredients, both in use and effectiveness in the future.
Silymarin has been used historically as a liver-specific agent.
The extract of the seed-like fruit (achene) of the milk thistle plant (Silybum marianum) is known as silymarin. Silymarin is actually a combination of the flavonolignans silybin, silydianin, and silychristin.
Silymarin comes in capsules, liquids and teas; silymarin (the chemical constituent thought to be responsible for milk thistle's medical benefits) does not dissolve well in water, so the teas are very weak. The most popular products are standardized extracts of silymarin. An average dose is 200mg of an extract standardized for 70-80% silymarin.
Milk Thistle Extract is many times more potent in antioxidant activity than vitamin E.
The plant contains B-sitosterol and is the main ingredient in Take Control and Benecol. It thus lowers cholesterol. It has been shown in studies to be effective in treating arteriosclerosis.
Silymarin is considered a liver protectant, a choleretic (moving bile), and a liver-specific antioxidant. It is also known to be protective of the liver by increasing its ability to detoxify numerous toxic substances, including pesticides and heavy metals (lead, mercury, cadmium, arsenic, etc.). In numerous clinical studies, silymarin has been shown to have positive effects in treating virtually every type of liver disease including cirrhosis, hepatitis, jaundice, and chemical- or alcohol-induced fatty liver. Milk thistle facilitates liver cell regeneration and can protect the liver from toxic damage.
Many people take milk thistle regularly to protect their livers from the effects of alcohol, heavy metals and drugs, and as needed after exposure to solvents, pesticides, bacteria from food poisoning or other toxins. Studies since the 1930s, conducted mainly in Germany, researched that the silymarin found in the herb works to stabilize liver cell membranes and act as an antioxidant to protect liver cells from free radical damage. It also helps regenerate healthy liver cells and boost the organ's ability to filter toxins from the blood.
Most recently researchers found that the antioxidant activity of a milk thistle seed extract reduced the liver damage typically seen in patients who take prescription anti-psychotic drugs for extended periods and particularly in death cap mushroom poisoning. Silymarin has been shown to prevent and even reverse the toxic affect of mushroom (Amanita phalloides) poisoning, which can cause death within 24 hours. It is able to do this by specifically blocking the receptor for these toxins.
The standard dose of milk thistle is based on its silymarin content, 70 to 210mg three times daily. For this reason, standardized extracts, typically 80% silymarin content, are preferred.
Silymarin preparations are widely used in Europe, where a considerable body of evidence points to very low toxicity even when used for long periods of time. There are no reported side-effects or contraindications. In fact, the plant's young (non-spiny) leaves and stems were once consumed as food in Europe.
Silymarin (the flavonoid extracted from milk thistle) and silymarin-derived compounds have been considered hepatoprotective (protecting the liver from damage) since the plant was first described in ancient times. More recently, it has been studied for treating all types of liver disease and the results have been encouraging but not yet conclusive due to the lack of large clinical studies.
It has been shown that silymarin has the ability to block fibrosis, a process that contributes to the eventual development of cirrhosis in persons with inflammatory liver conditions secondary to alcohol abuse or hepatitis [Schuppan D, Strösser W, Burkard G, Walosek G. Legalon® lessens fibrosing activity in patients with chronic liver diseases. Zeits Allgemeinmed 1998;74: pp.577-84]. This action makes milk thistle extract potentially attractive to persons with chronic hepatitis C – particularly those who have not responded to standard drug therapy.
For acute hepatitis, double-blind studies have shown mixed results.  A preparation of silymarin complexed with phosphatidylcholine was reported to help sufferers of chronic viral hepatitis. One small pilot study found that at least 420mg of silymarin was necessary each day. A controlled investigation found that silymarin decreased liver damage. One study has suggested that silymarin may be more effective for hepatitis B as opposed to hepatitis C.
Silybum Marianum (80% extract), 200 to 300mg three times per day, protects the liver. It may also be used as phosphatidylcholine-bound silymarin (100 to 150mg three times per day).
 Magliulo E, Gagliardi B, Fiori GP. Results of a double blind study on the effect of silymarin in the treatment of acute viral hepatitis carried out at two medical centers. Med Klin 1978;73: pp.1060-5 [in German]
 Bode JC, Schmidt U, Durr HK. Silymarin for the treatment of acute viral hepatitis? Report of a controlled trial. Med Klin 1977;72: pp.513-8 [in German]
 Vailati A, Aristia L, Sozze E, et al. Randomized open study of the dose-affect relationship of a short course of IdB 1016 in patients with viral or alcoholic hepatitis. Fitoterapia 1993;64:219-27
 Buzzelli G, Moscarella S, Giusti A, et al. A pilot study on the liver protective effect of silybin-phosphatidylcholine complex (IdB 1016) in chronic active hepatitis. Int J Clin Pharmacol Ther Toxicol 1993;31: pp.456-60
 Lirussi F, Okolicsanyi L. Cytoprotection in the nineties: experience with ursodeoxycholic acid and silymarin in chronic liver disease. Acta Physiol Hung 1992;80: pp.363-7
Milk thistle is renowned for its ability to support and stimulate the liver, the organ primarily responsible for ridding the body of alcohol. Some recommend taking 500mg of milk thistle before embarking on a long night of drinking, and if the session is particularly heavy, taking 350mg three times daily for a couple of days thereafter.
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