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MILK THISTLE

Other Names:

Artichaut Sauvage, Blessed Milk Thistle, Cardo Lechoso, Cardui Mariae Fructus, Cardui Mariae Herba, Carduus Marianum, Carduus marianus, Chardon Argenté, Chardon de Marie, Chardon de Notre-Dame, Chardon Marbré, Chardon-Marie, Épine Blanche, Holy ...
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milk thistle Overview
milk thistle Uses
milk thistle Side Effects
milk thistle Interactions
milk thistle Dosing
milk thistle Overview Information

Milk thistle is a plant. The above ground parts and seeds are used to make medicine. The seeds are more commonly used.

Milk thistle is used most often for liver disorders, including liver damage caused by chemicals, Amanita phalloides mushroom poisoning, jaundice, chronic inflammatory liver disease, cirrhosis of the liver, and chronic hepatitis. Nevertheless, researchers have not yet concluded with certainty that milk thistle is effective for any of these uses.

Milk thistle is also used for loss of appetite, heartburn (dyspepsia), and gallbladder complaints.

Some people use milk thistle for diabetes, hangover, diseases of the spleen, prostate cancer, malaria, depression, uterine complaints, increasing breast milk flow, allergy symptoms, and starting menstrual flow.

In foods, milk thistle leaves and flowers are eaten as a vegetable for salads and a substitute for spinach. The seeds are roasted for use as a coffee substitute.

Milk thistle gets its name from the milky sap that comes out of the leaves when they are broken. The leaves also have unique white markings that, according to legend, were the Virgin Mary’s milk. Don’t confuse milk thistle with blessed thistle (Cnicus benedictus).

How does it work?

Milk thistle seed might protect liver cells from toxic chemicals and drugs. It also seems to have antioxidant and anti-inflammatory effects. Milk thistle plant extract might enhance the effects of estrogen.

milk thistle Uses & Effectiveness What is this?

Possibly Effective for:

  • Seasonal allergies (allergic rhinitis). Some research shows that people who take a milk thistle extract in combination with a conventional antihistamine have reduced symptoms compared to people who just use an antihistamine.
  • Diabetes. Some research shows that taking silymarin, a chemical found in milk thistle, along with conventional treatment can decrease blood sugar, total cholesterol, low-density lipoprotein (LDL or “bad”) cholesterol, and triglycerides in people with diabetes.
  • Heartburn (dyspepsia). When used daily for 4 weeks, a specific combination product (Iberogast, Medical Futures, Inc) that contains milk thistle plus peppermint leaf, German chamomile, caraway, licorice, clown’s mustard plant, celandine, angelica, and lemon balm seems to reduce the severity of acid reflux, stomach pain, cramping, nausea, and vomiting.
  • Menopausal symptoms. Research in women suggests that taking a specific product containing milk thistle, black cohosh, dong quai, red clover, American ginseng, and chasteberry (Phyto-Female) twice daily for 3 months reduces menopausal symptoms, including hot flashes and night sweats.
  • Skin damage caused by radiation treatment. Research suggests that applying a specific product (Leviaderm) containing silymarin, a certain chemical found in milk thistle, to the skin reduces skin damage caused by radiation treatment in women with breast cancer.
Most studies of milk thistle’s effectiveness have used a specific extract standardized to 70% to 80% silymarin. In the U.S., this formulation is found in the brand name product Thisilyn (Nature’s Way).


Possibly Ineffective for:

  • Obsessive-compulsive disorder (OCD). Research shows that taking milk thistle for 8 weeks does not improve OCD symptoms.
  • Hepatitis B. Most clinical evidence suggests that milk thistle or specific chemicals from milk thistle do not improve liver function or reduce the risk of mortality in patients with hepatitis B.
  • Hepatitis C. Most clinical evidence suggests that milk thistle or specific chemicals from milk thistle do not improve liver function or reduce the risk of mortality in patients with hepatitis C.

Insufficient Evidence for:

  • Liver disease caused by excessive use of alcohol. There is conflicting evidence about the effectiveness of milk thistle for treating alcohol-related liver disease. Early research suggests that taking milk thistle by mouth might improve liver function and reduce risk of death. However, other research suggests it may not have an effect.
  • Alzheimer’s disease. Early research suggests that taking a combination supplement containing silymarin, a chemical found in milk thistle, seems to improve mental function in people with Alzheimer’s disease.
  • Amanita mushroom poisoning. Giving silibinin, a chemical found in milk thistle, intravenously (by IV) may lessen liver damage caused by Amanita phalloides mushroom (death cap) poisoning. However, it is hard to obtain silibinin in the U.S.
  • Chemotherapy toxicity. Early research suggests that taking a milk thistle product containing the chemical silibinin beginning at the start of chemotherapy treatment does not significantly reduce liver toxicity caused by chemotherapy.
  • Liver scarring (cirrhosis). Early research suggests that milk thistle or silymarin, a chemical found in milk thistle, might reduce the risk of death and improve liver function in people with cirrhosis. However, milk thistle does not seem to benefit all patients with liver disease when those without cirrhosis are also considered.
  • Kidney disease in people with diabetes. Early research shows that taking silymarin, a chemical found in milk thistle, together with conventional treatment might help treat kidney disease in people with diabetes.
  • Kidney failure treatment (hemodialysis). Early research suggests that taking a chemical found in milk thistle might increase levels of hemoglobin, a protein in red blood cells that carries oxygen, in people undergoing hemodialysis.
  • Hepatitis. Research on the effects of milk thistle for treating hepatitis is inconsistent. Early research suggests that taking a specific product (Silipide) containing silybin, a chemical found in milk thistle, might improve liver function in people with long-term (chronic) hepatitis. Other research shows that a specific product (Legalon) containing the milk thistle chemical called silymarin can improve liver function in people with short-term (acute) hepatitis. However, conflicting results exists regarding the benefit of Legalon. Other research suggests that a different milk thistle product (Sylimarol), taken in combination with vitamins B and C, does not improve liver function in people with short-term (acute) viral hepatitis. Most research suggests that milk thistle or chemicals from milk thistle do not improve liver function or reduce the risk of death from hepatitis B or hepatitis C.
  • High cholesterol. Evidence about how milk thistle affects cholesterol is inconsistent. Early evidence suggests that taking silymarin, a chemical found in milk thistle, does not affect cholesterol levels in people with high cholesterol. However, other research shows that taking the same chemical can reduce total cholesterol, low-density lipoprotein (LDL or “bad”) cholesterol, and triglycerides in people with diabetes and high cholesterol.
  • Infertility. Early research shows that taking silymarin, a chemical found in milk thistle, along with fertility hormones might provide some benefits for women undergoing in vitro fertilization due to male infertility.
  • Multiple sclerosis. Early research suggests that taking a combination supplement containing silymarin, a chemical found in milk thistle, can improve mental function and promote disease stabilization in people with multiple sclerosis.
  • Parkinson’s disease. Early research suggests that taking a combination supplement containing silymarin, a chemical found in milk thistle, improves mental function and promotes disease stabilization in people with Parkinson’s disease.
  • Prostate cancer. Prostate-specific antigen (PSA) is a protein in the blood that can be measured to diagnose and monitor prostate cancer. Early research suggests that taking a supplement containing silymarin, a chemical found in milk thistle, can delay the rise in PSA levels in men with a history of prostate cancer.
  • Liver damage caused by chemicals. Early research suggests that milk thistle may limit liver damage caused by exposure to industrial poisons such as toluene and xylene. However, there is some inconsistent evidence. Taking silymarin, a chemical found in milk thistle, does not seem to improve liver damage caused by tarcine, a medicine used to treat Alzheimer’s. However, taking silibinin, another chemical found in milk thistle, seems to improve test results for liver damage caused by tuberculosis medications.
  • Spleen disorders.
  • Gallbladder problems.
  • Swelling of the lungs (pleurisy).
  • Malaria.
  • Menstrual problems.
  • Other conditions.
More evidence is needed to rate the effectiveness of milk thistle for these uses.


milk thistle Side Effects & Safety

Milk thistle is LIKELY SAFE when taken by mouth for most adults. Milk thistle sometimes causes a laxative effect. Other less common side effects are nausea, diarrhea, indigestion, intestinal gas, bloating, fullness or pain, and loss of appetite.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Not enough is known about the use of milk thistle during pregnancy and breast-feeding. Stay on the safe side and avoid use.

Allergy to ragweed and related plants: Milk thistle may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae plant family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, be sure to check with your healthcare provider before taking milk thistle.

Diabetes: Certain chemicals in milk thistle might lower blood sugar in people with diabetes. Dosing adjustments to diabetes medications might be necessary.

Hormone-sensitive conditions such as breast cancer, uterine cancer, ovarian cancer, endometriosis, or uterine fibroids: Extracts from milk thistle PLANT might act like estrogen. If you have any condition that might be made worse by exposure to estrogen, don’t use these extracts. In contrast, the more commonly used milk thistle SEED extracts do not seem to act like estrogen.

milk thistle Interactions What is this?

Moderate Interaction Be cautious with this combination

  • Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates) interacts with MILK THISTLE

    Some medications are changed and broken down by the liver.
    Milk thistle might decrease how quickly the liver breaks down some medications. Taking milk thistle along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking milk thistle talk to your healthcare provider if you take any medications that are changed by the liver.
    Some medications that are changed by the liver include amitriptyline (Elavil), diazepam (Valium), zileuton (Zyflo), celecoxib (Celebrex), diclofenac (Voltaren), fluvastatin (Lescol), glipizide (Glucotrol), ibuprofen (Advil, Motrin), irbesartan (Avapro), losartan (Cozaar), phenytoin (Dilantin), piroxicam (Feldene), tamoxifen (Nolvadex), tolbutamide (Tolinase), torsemide (Demadex), warfarin (Coumadin), and others.

  • Medications changed by the liver (Glucuronidated Drugs) interacts with MILK THISTLE

    The body breaks down some medications to get rid of them. The liver helps break down these medications. Taking milk thistle might affect how well the liver breaks down drugs. This could increase or decrease how well some of these medications work.
    Some of these medications changed by the liver include acetaminophen, atorvastatin (Lipitor), diazepam (Valium), digoxin, entacapone (Comtan), estrogen, irinotecan (Camptosar), lamotrigine (Lamictal), lorazepam (Ativan), lovastatin (Mevacor), meprobamate, morphine, oxazepam (Serax), and others.


Minor Interaction Be watchful with this combination

  • Estrogens interacts with MILK THISTLE

    Milk thistle might decrease hormones in the body. Milk thistle might help the body break down estrogen pills to get rid of them. Taking milk thistle along with estrogens might decrease the effectiveness of estrogen pills.
    Milk thistle contains a chemical called silymarin. Silymarin might be the part of milk thistle that helps the body break down estrogens.
    Some estrogen pills include conjugated equine estrogens (Premarin), ethinyl estradiol, estradiol, and others.

  • Medications used for lowering cholesterol (Statins) interacts with MILK THISTLE

    Theoretically, milk thistle might change the levels of some medications used for lowering cholesterol (statins). This could increase or decrease how well these medications work.
    Some medications used for lowering cholesterol include atorvastatin (Lipitor), fluvastatin (Lescol), lovastatin (Mevacor), pravastatin (Pravachol), and rosuvastatin (Crestor).


milk thistle Dosing

The following doses have been studied in scientific research:

BY MOUTH:

  • For seasonal allergies (allergic rhinitis): Milk thistle extract of silymarin 140 mg three times daily.
  • For upset stomach (dyspepsia): A specific combination product containing milk thistle (Iberogast, Medical Futures, Inc) and several other herbs has been used in a dose of 1 mL three times daily.

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Conditions of Use and Important Information: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version. © Therapeutic Research Faculty 2009.

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