Milk thistle is extraordinarily useful in the treatment of liver diseases such as alcoholic hepatitis, cirrhosis, liver poisoning, and viral hepatitis. Milk thistle is one of the few herbs that have no real pharmaceutical equivalent. It reduces inflammation and is an antioxidant. Traditionally used for functional disorders of the liver and gallbladder such as jaundice, it was also used to treat malaria.

Today it is used for dyspepsia, toxic liver, and hepatic cirrhosis. The German Commission E has approved milk thistle for dyspeptic, liver, and gallbladder complaints. According to the German Commission E, milk thistle works in two ways: It alters the structure of the outer cell membrane of the liver cells to prevent toxins such as from food poisoning from getting inside the liver cells, and second, it stimulates the action of nucleolar polymerase A, which stimulates the regeneration of new, healthy liver cells.

Botanical Name

Silybum marianum

Part Used

Fruit (Seed)

Common Names

lady’s thistle, Marian thistle, Mary thistle, St. Mary thistle, Silybum, holy thistle; emetic root, snake milk, milk ipecac

Brief History

Silymarin is poorly soluble in water, so aqueous preparations such as teas are ineffective, except for use as a supportive treatment in gallbladder disorders because of cholagogic and spasmolytic effects. The drug is best administered parenterally because of poor absorption of silymarin from the gastrointestinal tract. The drug must be concentrated for oral use.

Silymarin’s hepatoprotective effects may be explained by its altering of the outer liver cell membrane structure, as to disallow entrance of toxins into the cell. This alteration involves silymarin’s ability to block the toxin’s binding sites, thus hindering uptake by the cell. Hepatoprotection by silymarin can also be attributed to its antioxidant properties by scavenging pro-oxidant free radicals and increasing intracellular concentration of glutathione, a substance required for detoxicating reactions in liver cells.

Silymarin’s mechanisms offer many types of therapeutic benefit in cirrhosis with the main advantage of being hepatoprotection. Use of milk thistle, however, is inadvisable in decompensated cirrhosis. In patients with acute viral hepatitis, silymarin shortened treatment time and showed improvement in serum levels of bilirubin, AST and ALT.


Silybum marianumIndigenous to Kashmir, naturalised as a weed in North America from Canada to Mexico, in dry, rocky areas, wastelands, and fields. Naturalised in Australia and on various noxious weed lists. Annual or biennial. Germination: 10- 15 days. Space 3 feet. Soil: well-drained, dry, very drought tolerant. pH: 6-8. Sun: Full. Propagation: by seed.


The main active ingredient in milk thistle is a group of flavonolignans collectively called silymarin. Silymarin consists of silybin (silibinin) AB, silydianin, silychristin, dehydrosilybinin, isosilybinin A B and others. Silybin is the main biologically active flavonolignan in silymarin.

Therapeutic Properties

Choleretic, cytoprotective, chemoprotective, digestive tonic, hepatoprotective, hepatotonic, antioxidant, cholagogue.

Vitalist Properties

Temperature: Cool

Moisture: Moist

Therapeutic Indications

Alcoholism, gallbladder disorders, liver insufficiency, toxicity or cirrhosis, hepatitis, jaundice, hypercholesterolaemia, nausea of pregnancy

Primary Uses

Alcoholism, cirrhosis, and hepatitis.

Silymarin, an extract of milk thistle, acts on the membranes of the liver cells, preventing the entry liverof virus toxins and other toxic compounds and thus preventing damage to the cells. It also dramatically improves liver regeneration in hepatitis, cirrhosis, mushroom poisoning, and other diseases of the liver. One study, conducted by a German pharmaceutical firm, looked at 2,637 people who had used milk thistle for various liver disorders, including cirrhosis of the liver, fatty liver, and hepatitis. After eight weeks of taking standardised milk thistle capsules daily, 63 percent of the study participants said their symptoms—including abdominal distention, fatigue, lack of appetite, and nausea—had disappeared. The average improvement in levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), enzymes that are markers for liver cell impairment, was 46 percent, and over 73 percent of enlarged livers shrank in size. Only 1 percent of the study participants were forced to discontinue milk thistle because of side effects, such as mild diarrhoea, nausea, and stomach upset.

Other studies focused on specific disorders also have shown positive results. In a well-documented double-blind study of 116 individuals who had alcoholic cirrhosis of the liver, German researchers found that milk thistle exerted a profound curative action in as little as two weeks. And in a later study, twenty-nine people with advanced alcoholic liver disease reported relief from nausea and restored appetite after two months’ treatment with the milk thistle extract silymarin. In cases of hepatitis B and hepatitis C, a flavonoid complex in silymarin stimulates liver protein creation, enabling the organ to produce new liver cells to replace the old ones damaged by hepatitis infection. This action prevents the replacement of virus-infected liver cells with fibrous tissues or fat.

In one study, patients with alcoholic cirrhosis and those with Child’s A group classification of portal hypertension taking 40 milligrams of silymarin three times a day for four years showed an improvement in symptoms and blood tests. Patients without alcoholic cirrhosis but who had Child’s B and C group hypertension did not show improvement. However, the survival rate of all subjects taking silymarin was better than those who didn’t take it (58 percent versus 39 percent).


There are no clinical data on cancer and milk thistle. However, milk thistle was shown to reduce liver toxicity associated with chemotherapy for children with acute lymphoblastic leukaemia. Some breast cancers (as well as other forms of cancer) are stimulated by the hormone oestrogen. Laboratory studies find that silybin, a chemical found in milk thistle, competes for the receptor sites that would receive oestrogen in these kinds of cancer cells. Scientists at Case Western Reserve University in Cleveland, Ohio, have found that silymarin stops the growth of breast cancer cells, both within tumours and, more important, before anchoring themselves in other organs of the body.
Rats given the milk thistle compound silibinin in a very large dosage (equivalent to 30 grams, or approximately 1 ounce, for a 110-pound [55-kilogram] adult) had reduced kidney damage during treatment with the cancer chemotherapy agent cisplatin (Platinol). Another study found that, in addition to protecting the kidneys from damage by either cisplatin or doxorubicin (Adriamycin), silybin increased the cancer-fighting effectiveness of the two drugs. Tests also indicate that silibinin protects against the toxic effects of cisplatin and ifosfamide (Ifex) therapy without diminishing these drugs’ effects on testicular cancers.

Milk thistle acts against liver cancer by protecting specialised immune cells in the liver known as Kuppfer cells. These cells engulf bacteria, toxins, and other foreign matter coming into the liver, and also play a role in destroying cancer cells that have entered blood circulation as a first step in spreading to other parts of the body. The silibinin in milk thistle protects the Kuppfer cells from inflammatory reactions without interfering with the action of an immune system chemical called tumour necrosis factor alpha, which accelerates the destruction of cancer cells by the immune system. Silibinin reduces PSA (prostate-specific antigen), which is released in prostate cancer. It also inhibits the G1 cycle of the cell cycle progression in prostate cancers that do not respond to any other chemotherapy. In stopping the G1 cycle, the cancer growth is arrested as well.


Insulin resistance is very difficult to treat and may be found in patients with cirrhosis of the liver caused by alcohol. In a double-blind study of sixty patients who had both alcoholic cirrhosis of the liver and diabetes, twelve months of treatment with 600 milligrams of silymarin daily resulted in significantly lower fasting blood glucose levels, less glucose spill over into the urine, and smaller proportions of glycosylated haemoglobin, which is a measurement of long-term elevated blood sugars.

Milk thistle may fight diabetes in other ways. Insulin not only transports glucose into muscle cells but also transports fatty acids into fat cells. Silymarin stimulates the liver so that it can take excessive amounts of insulin out of the bloodstream in people with type 2 diabetes or diabetes arising from alcoholic damage to the liver. By regulating the amount of insulin in circulation, silymarin treatment may prevent weight gain, which usually accompanies excessive amounts of insulin in the bloodstream. Also, animal studies indicate that milk thistle extract can reduce ketoacidosis, a complication of prolonged, uncontrolled diabetes in which the body is forced to use fats rather than glucose for fuel, producing potentially toxic effects on the central nervous system.

Clinical Research

  • Silymarin treatment significantly reduced serum levels of hepatic enzymes, significantly improved platelet counts, and improved nausea, discomfort, and skin itching in patients with toxic liver damage of differing origins in uncontrolled trials.
  • Silymarin improved biochemical, functional, and morphologic alterations in the livers of patients with slight acute and subacute liver disease in a double-blind, placebo-controlled, clinical trial.
  • Silymarin reduced lipoperoxidation of cell membranes and insulin resistance and significantly decreased insulin overproduction and the need for insulin in a controlled study involving patients with insulin-dependent diabetes and alcoholic cirrhosis.
  • In other controlled studies involving patients with alcoholic liver disease, silymarin demonstrated a significant reduction of hepatic enzymes and bilirubin and improvements in antioxidant and lipid peroxidation parameters. Other studies reported statistically insignificant improvements, but continuing alcohol consumption may have confounded the experimental results.
  • Silymarin treatment significantly increased survival rates in patients with cirrhosis of different causes (especially alcoholic cirrhosis) in long-term, randomised, double-blind trials.
  • Well-controlled clinical studies of the treatment of various types of hepatitis with silymarin have produced mixed results, with some studies demonstrating significant reductions in serum liver enzymes and bilirubin and others not.
  • Silymarin, given preoperatively and postoperatively, prevented the increase of serum hepatic enzymes induced by the toxic effect of general anaesthesia.
  • In a randomised, double-blind, placebo-controlled study, silymarin reduced the lipoperoxidative hepatic damage that occurs during psychotropic drug treatment.
  • Silymarin protected against histologic changes in the livers of pregnant women and those taking oral contraceptives.
  • In both cholelithiasis and cholecystectomised patients, silymarin reduced biliary cholesterol concentration and bile saturation compared with placebo.
  • In Germany, the Commission E supports using galenical preparations of milk thistle to treat dyspeptic complaints. Extracts standardised to contain at least 70% silymarin are recommended for toxic liver damage, as supportive treatment in chronic inflammatory liver disease, and for hepatic cirrhosis.

Dosage (Divided Daily)

Dried Seed: 6,000 – 9,000mg

• Extract: 500 – 2,000mg (80% Silymarin/30% Silybin) Take with Soy Lecithin to considerably increase absorption.

• Tincture: 4.5 – 8.5 mL (1:1)

Buy Milk Thistle Extract Loose Powder or Capsules
Milk Thistle Seed Powder


None known

Side effects

May cause gastric upset in a small percentage of cases.

A mild laxative effect may occasionally occur.

Interactions with other drugs

None known.


  1. Balch, P. A., & Bell, S. J. (2012). Prescription for herbal healing (2nd ed.). New York, N.Y.: Avery.

  2. Bone, K. (2003). A clinical guide to blending liquid herbs: herbal formulations for the individual patient. St. Louis, MI: Churchill Livingstone.
  3. Herbalpedia (2013)
  4. Mars, B. (2007). The desktop guide to herbal medicine: the ultimate multidisciplinary reference to the amazing realm of healing plants, in a quick-study, one-stop guide. Laguna Beach, CA: Basic Health Pub.
  5. Mills, S., & Bone, K. (2000). Principles and practice of phytotherapy: modern herbal medicine. Edinburgh; London: Churchill Livingstone. 

All material on this website is provided for your information only and may not be construed as medical advice or instruction. No action or inaction should be taken based solely on the contents of this information; instead, readers should consult appropriate health professionals on any matter relating to their health and well-being.

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