Milk Thistle

What is it?

• 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, 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 effective is it?

Possibly effective for

• Heartburn (dyspepsia), when a combination of milk thistle and several other herbs is used. The combination product (Iberogast, Medical Futures, Inc) contains milk thistle plus peppermint leaf, German chamomile, caraway, licorice, clown’s mustard plant, celandine, angelica, and lemon balm. When used daily over a period of 4 weeks, this combination seems to reduce severity of acid reflux, stomach pain, cramping, nausea, and vomiting. 
• Diabetes. A compound in milk thistle called silymarin appears to lower blood sugar in people with type 2 diabetes. 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).

Insufficient evidence to rate effectiveness 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. 
• Amanita mushroom poisoning. Giving silibinin, a chemical found in milk thistle, intravenously (by IV) may lessen liver damage due to Amanita phalloides mushroom (death cap) poisoning. However, it is hard to get silibinin in the U.S. 
• Hepatitis B or hepatitis C. Milk thistle and some of the chemicals in it do not seem to improve survival or decrease liver function tests in people with hepatitis B or C. 
• Liver disease caused by chemicals. Some research suggests milk thistle may limit liver damage after exposure to industrial poisons such as toluene and xylene. 
• 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.

How does it work?

Are there safety concerns?

• Milk thistle is LIKELY SAFE 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.
• 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.

Are there interactions with medications?

Moderate