Milk Thistle Side Effects and Drug Interaction

Milk thistle (Silybum sp.) is a native plant of the Mediterranean region. It is highly regarded medicinal plant because it is the source of silymarin – a mixture of biologically active polyphenolic compounds that have hepatoprotective effects. Silymarin is usually extracted from the seeds. Silymarin has many health benefits: protects the liver against deathcap mushroom poisoning; protects the liver from toxins; improves liver function in patients with cirrhosis and hepatitis; exhibits anti-cancer properties; contains antioxidants that scavenge free radicals, and; reduces the side effects of chemotherapy. Read more about the health benefits of milk thistle.

Side Effects of Milk Thistle/Silymarin

It has been found out in clinical trials that silymarin is well-tolerated by participants if given in recommended doses. The recommended dose is 280-450 mg per day in divided doses. If silymarin-phosphatidylcholine is to be given, the recommended dose is 100-200 mg two times a day. The dose of silymarin-phosphatidylcholine is lower because it is absorbed faster than silymarin alone. Phosphatidylcholine, a major component of cell membrane, helps silymarin attach easily to cell membranes of liver cells.

Common side effects of milk thistle are indigestion, diarrhea, heartburn, and bloating. Some people can be allergic to milk thistle; symptoms include itching, rashes, swelling, nausea, vomiting, difficulty breathing, and anaphylactic shock. People who are allergic to daisies, artichokes, kiwi, common thistle or plants in the Aster family are most likely to be allergic to milk thistle. (Milk thistle belongs to the Aster family). In case of milk thistle allergy, seek the help of a healthcare provider.

The safety of milk thistle in pregnant and breastfeeding women has not been extensively studied. They should consult their doctor first before taking milk thistle products.

Milk thistle can lower blood sugar levels so people with diabetes and hypoglycemia sugar should use it with caution. Those taking medications affecting blood sugar should also use milk thistle with caution.

Milk thistle has estrogen-like properties so it should not be used by people with hormone-sensitive health problems such as endometriosis and cancers in the prostate, ovaries, uterus, and breast.

Milk Thistle Drug Interactions

People who are taking different medications should first consult their doctor before using milk thistle to avoid possible adverse drug interaction. Medications known to interact with milk thistle include antipsychotics, phenytoin, halothane, anticoagulant & anti-platelet drugs, anti-anxiety drugs, allergy drugs, drugs for high blood cholesterol, and some cancer drugs.[ad#afterpost]

Milk Thistle – University of Maryland Medical Center

Milk Thistle – National Center for Complementary and Alternative Medicine