Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Milk thistle is a flowering herb from the Mediterranean. People have traditionally used milk thistle for problems with the liver and gallbladder. Silymarin is an antioxidant compound taken from milk thistle seeds. Experts believe silymarin is the primary active ingredient of the herb.

Why do people take milk thistle?

Research has backed up some uses of milk thistle for liver health. It may have protective effects on the liver, preventing damage. There’s good evidence that milk thistle can help treat cirrhosis and chronic hepatitis, which can be caused by alcohol abuse, autoimmune disease, or viruses. However, experts say that the evidence isn’t conclusive.

Some studies have also shown that milk thistle, in combination with medical treatment, may help improve blood sugar and cholesterol in people with type 2 diabetes. More research is needed to confirm these effects.

How much milk thistle should you take?

Optimal doses of milk thistle have not been established for any condition. 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 health care provider 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?

  • Side effects. Milk thistle seems to have few side effects, even when taken for years. Some people have nausea, diarrhea, itching, and bloating.
  • Risks. Milk thistle can trigger allergic reactions. People who are allergic to artichokes, kiwi, ragweed, daisies, marigolds, and chrysanthemums are at higher risk. Those 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. So, if you’re either pregnant or breastfeeding, check with your health care provider before using milk thistle. Milk thistle is not recommended for children.
  • Interactions. If you take any medicines regularly, talk to your health care provider before you start using milk thistle. It could interact with drugs for fungal infections, bacterial infections, and insomnia. Since milk thistle may lower blood sugar, people with diabetes should use caution when taking the herb so that their blood sugar doesn’t fall too low.

Savings Poll

How do you save money on vitamins and supplements?

View Results