Milk Thistle

Health Tips / Milk Thistle

What Is It?

Healers have used the prickly milk thistle plant to treat liver ailments for more than 2,000 years. Somehow these early practitioners figured out that preparations of this purple-flowered member of the sunflower family could stimulate the flow of bile from the liver, improving digestion and various liver-related ills.

Interestingly, bile and other bodily fluids, also known as humors, were once associated with different personality types. Because it was thought that black bile was inherent to a melancholic nature, milk thistle was prescribed for treating depression and melancholy (which actually means “black bile”). Today, the word “biliousness” and the phrase “having excess bile” are still used to describe negative personality traits.

While milk thistle is no longer seen as a remedy for melancholy, hundreds of medical studies have substantiated the fact that the herb does indeed protect and heal the liver. European physicians currently consider milk thistle a mainstay for liver disorders ranging from hepatitis to cirrhosis. But even though a 19th-century American medical group called the Eclectics prescribed milk thistle for liver ailments, it has never been widely used in the U.S. for healing purposes.

Milk thistle grows throughout the world (including North America) in both cultivated and wild form. Many sources refer to the herb, by its botanical name, Silybum marianum, as well as by its active compounds, collectively known as silymarin. Concentrated stores of silymarin are found in the herb’s shiny black fruits (seeds), which are typically collected at summer’s end.

Health Benefits

Although most widely associated with liver complaints, milk thistle is also being examined for treating a variety of other disorders, from gallstones and high cholesterol to skin cancers and allergy symptoms. As a potent antioxidant, the versatile milk thistle extract helps prevent highly reactive oxygen molecules called free radicals from damaging cells throughout the body, but especially in the liver, stomach, and intestines.

An injectable form of milk thistle is a powerful antidote to mushroom poisoning. And the oral extract shows promise for minimizing chemotherapy-associated liver damage. This is a function of the herb’s antioxidant actions as well as its ability to accelerate the excretion of toxic compounds that can accumulate in the body.

Specifically, milk thistle may help to:

Treat acute and chronic liver disease. Milk thistle “cleanses” and therefore fortifies the liver, a vital organ responsible for processing everything from nutrients in foods to medications and chemical pollutants. The herb partly accomplishes this task by preventing a reduction in concentrations of glutathione, an amino-acidlike compound that is critical to neutralizing toxins. Some studies indicate that milk thistle can actually increase glutathione levels by as much as 35%.
In addition, silymarin alters the outer membrane of liver cells in such a way that toxins are barred from entering. It even encourages the formation of new, healthier liver cells to replace old, damaged ones. Various types of liver damage benefit from these remarkable properties, and the herb has repeatedly demonstrated its power to do so.

In the largest trial to date specifically studying the use of milk thistle for chronic liver disease, more than 2,500 people suffering from this condition showed improvement in their liver function tests when taking the extract. Many also reported that they felt better. People with an acute form of liver disease–acute viral hepatitis–also stand to benefit from milk thistle. In a double-blind study reported in 1998, the extract improved the results of liver function tests, speeded recovery, and reduced the length of hospital stays as compared with a placebo.

Treat alcochol-related liver problems. Excessive alcohol intake depletes the amount of toxin-neutralizing glutathione in the liver and can cause severe scarring and dysfunction, a condition called cirrhosis. Milk thistle not only boosts glutathione levels, it also helps to actually repair the liver by promoting the growth of new cells in this large and vital organ.
An important 1989 trial of patients with chronic alcoholic hepatitis is frequently cited to demonstrate the extract’s powers. In the study, liver function test results returned to normal and overall liver health improved over six months in those who took milk thistle instead of a placebo.

Control psoriasis. The herb has anti-inflammatory properties that may be useful for keeping the charasteristic psoriasis rash in check and for slowing the proliferation of abnormal skin cells.



Dosage Information

Special tip:

To work as effectively as indicated in dozens of clinical trials, milk thistle needs to be correctly prepared and standardized. Choose a supplement standardized to contain 70% to 80% silymarin, the active ingredient. This high concentration of silymarin is needed to ensure that a sufficient amount will reach the bloodstream and eventually the liver.

For all forms of liver problems, including alcohol-related ones: Take 400 to 600 mg standardized extract a day divided into three doses.

Guidelines for Use

Don’t expect teas made with milk thistle to improve any medical condition. Unfortunately, they contain only trace amounts of silymarin, which dissolves poorly in water. Also avoid products containing milk thistle leaf; they have no therapeutic value.

There are products now available in which silymarin is chemically bound to phosphatidylcholine, a key component of lecithin (a natural fat). These preparations may in fact be better absorbed and more effective than regular milk thistle.

Herbal blends that go by such names as”liver complex” and “lipotropic factors” combine milk thistle with other herbs and nutrients. Popular ingredients include dandelion, methionine, inositol, and choline, compounds believed to enhance liver function and increase the flow of fats and bile from the liver and gallbladder.

Take milk thistle 30 minutes before meals for optimal effectiveness.

Keep in mind that it will take at least a week or two before you notice milk thistle’s beneficial effects. For chronic conditions, you will need to take the herb for quite some time.

General Interaction

There are no known drug or nutrient interactions associated with taking milk thistle.

Possible Side Effects

Although generally acknowledged as extremely safe, some individuals have reported mild cases of diarrhea.


Don’t try to self-diagnose or self-treat a liver problem. Such ailments require the attention of a medical professional who can closely monitor your care.

Avoid alcohol-based tinctures of milk thistle. Some of these contain considerable amounts of alcohol, which can damage the liver over time.

Milk thistle is widely accepted as safe, even for women who are pregnant or breast-feeding.


Alcoholism 120-175 mg 3 times a day between meals
Gallstones 100-175 mg 2 or 3 times a day
Hepatitis 150-300 mg 3 times a day OR 1/2 tsp. liquid extract 3 times a day
Psoriasis 120-175 mg of standardized extract or 1/2 tsp. liquid extract twice a day

Be well,
David Edelberg, MD