Menu

Milk Thistle: Benefits and Side Effects

Medically Reviewed by James Beckerman, MD, FACC on June 09, 2021

Milk thistle (silymarin) is a flowering herb related to the daisy and ragweed family. It is native to Mediterranean countries. Some people also call it Mary thistle and holy thistle.

What Is Milk Thistle Used For?

People have traditionally used milk thistle for problems with the liver and gallbladder . Experts believe silymarin is the primary active ingredient of the herb. Silymarin is an antioxidant compound taken from milk thistle seeds. It’s unclear what benefits, if any, it may have in the body, but it’s sometimes used as a natural treatment for things including cirrhosis, jaundice, hepatitis, and gallbladder disorders.

Some claim milk thistle may also:

Is Milk Thistle Good for the Liver?

There’s conflicting research on the benefits of milk thistle for liver health. It may have protective effects on the liver, preventing damage. There’s some evidence that milk thistle can treat cirrhosis and chronic hepatitis, which can be caused by alcohol abuse, autoimmune disease, or viruses. But experts say that the evidence isn’t conclusive.

Some studies also show milk thistle may help people whose liver is damaged by industrial toxins, such as toluene and xylene.

There is not enough scientific data to say whether or not milk thistle can help liver problems. Get the facts on milk thistle for the liver.

Can Milk Thistle Help People With Diabetes?

Medical research suggests that milk thistle, combined with traditional treatment, can improve diabetes. Studies have shown a decrease in blood sugar levels and an improvement in cholesterol in people with type 2 diabetes.

Researchers also have found that milk thistle improved insulin resistance, a key part of type 2 diabetes.

Talk to your doctor before taking any supplements because they might interfere with your medication. Learn more about natural remedies for type 2 diabetes.

Is Milk Thistle Good for the Heart?

By lowering LDL "bad" cholesterol levels, milk thistle may lower the chance of developing heart disease. But studies on heart benefits have only been done in people with diabetes. People with diabetes often have high cholesterol. It’s unclear if milk thistle has the same effects in people without diabetes.

Milk thistle can also be taken with cholesterol-lowering medications, like statins. It can help prevent elevation of liver enzymes, which can be a side effect of the medication. Find out more on the side effects of statins.

How Much Milk Thistle Should You Take?

The best doses of milk thistle have not been established for any condition it may be used to treat. Quality and active ingredients in supplements may vary widely from maker to maker. This makes it very hard to establish a standard dose. Ask your doctor for advice.

Can You Get Milk Thistle Naturally From Foods?

People sometimes eat the stem and leaves of milk thistle in salads. There are no other food sources of this herb.

What Are the Risks of Taking Milk Thistle?

Risks. Milk thistle can trigger allergic reactions. People who are allergic to artichokes, kiwi, ragweed, daisies, marigolds, and chrysanthemums are at higher risk. People who have diabetes or endometriosis should check with a doctor before using milk thistle. While milk thistle has been traditionally used in pregnant and breastfeeding women, its safety is unknown. If you’re pregnant or breastfeeding, check with your doctor before using milk thistle. Milk thistle is not recommended for children.

Side effects. Milk thistle seems to have few side effects, even when taken for several years. Some people have nausea, diarrhea, itching, and bloating.

Interactions. If you take any medicines regularly, talk to your doctor before you start using milk thistle. It could interact with many drugs, including some that treat high cholesterol, infections, insomnia, and blood pressure. Since milk thistle may lower blood sugar, people with diabetes should check with their doctor before taking the herb as it may make their blood sugar fall too low.

WebMD Medical Reference

Sources

SOURCES:

Natural Medicines Comprehensive Database: "Milk Thistle Monograph."

National Center of Complementary and Alternative Medicine (NCCAM): "Milk Thistle," “Herbs at a Glance: Milk thistle.”

Medicinenet.com: "Generic Name: Milk Thistle – Oral."

Longe, J., ed. The Gale Encyclopedia of Alternative Medicine, second edition, 2004.

Memorial Sloan-Kettering Cancer Center: “About Herbs: Milk thistle.”

Natural Standard Patient Monograph: “Milk thistle.”

Era of Hope Meeting for the Department of Defense Breast Cancer Research Program, Atlanta, June 8-11, 2000.

© 2021 WebMD, LLC. All rights reserved.
Click to view privacy policy and trust info