Plant Description

Milk thistle is native to the Mediterranean region. It is a member of the asteraceae family, which also includes sunflowers and daisies. It is now found throughout the world. This stout thistle usually grows in dry, sunny areas. Spiny stems branch at the top and reach heights of 5 to 10 feet. The leaves are wide with white blotches or veins. Milk thistle gets its name from the milky white sap that comes from the leaves when they are crushed. The flowers are red purple. The small, hard-skinned fruit is brown, spotted, and shiny. Milk thistle spreads quickly (it is considered a weed in some parts of the world), and it matures in less than a year.

What's It Made Of?

The active ingredient -- the one that protects the liver -- in milk thistle is known as silymarin, a chemical extracted from the seeds. Silymarin is actually a group of flavonoids ( silibinin , silidianin , and silicristin ), which are thought to help repair liver cells damaged by alcohol and other toxic substances. Silymarin also protects new liver cells from being destroyed by these same toxins. It reduces inflammation (which is why it is often suggested for people with liver inflammation or hepatitis) and is a strong antioxidant.

Most milk thistle products are standardized preparations made from the seeds of the plant, to contain 70% to 80% of silymarin.

Available Forms

• Capsules of standardized dried herb (each capsule contains about 120mg to 140 mg of silymarin)
• Liquid extract
• Tincture
• Silymarin phosphatidylcholine complex

A few studies show that a silymarin-phosphatidylcholine complex may be absorbed more easily than regular standardized milk thistle. Phosphatidylcholine is a key element in cell membranes. It helps silymarin attach easily to cell membranes, which may keep toxins from getting inside liver cells. People who have alcohol-related liver disease should avoid alcohol extracts.

How to Take It

Pediatric

There are no studies showing whether or not it is safe to give milk thistle to a child. Liver problems can be serious and should be diagnosed by a physician. Talk to your child's doctor before giving milk thistle to a child.

Adult

If you think you have a liver problem, you should see a doctor. Liver disease can be life threatening.

Precautions

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects, and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care practitioner.

Milk thistle is generally regarded as safe. Side effects are usually mild and may involve:

• Stomach upset
• Diarrhea
• Nausea and vomiting
• Rash (from touching milk thistle plants)

Milk thistle should not be used by pregnant or breastfeeding women.

People with a history of hormone-related cancers, including breast, uterine, and prostate cancer, should not take milk thistle.

DO NOT take milk thistle if you are allergic to ragweed, chrysanthemums, marigolds, chamomile, yarrow, or daisies.

Possible Interactions

Given milk thistle's action on the liver, the stie of most drug metabolism, it would be wise to speak to your doctor if you are taking any medication before using milk thistle. In particular, if you are being treated with any of the following medications, you should not use milk thistle without talking to your doctor first.

• Antipsychotics. Includes butyrophenones (such as haloperidol) and phenothiazines (such as chlorpromazine, fluphenazine, and promethazine).
• Phenytoin (Dilantin). A medication used for seizures.
• Halothane. A medication used during general anesthesia.
• Birth control pills or hormone replacement therapy.

Milk thistle may interfere with the following medications, because both milk thistle and these medications are broken down by the same liver enzymes:

• Allergy drugs. Such as fexofenadine (Allegra) .
• Drugs for high cholesterol. Including statins such as lovastatin (Mevacor, Altocor).
• Anti-anxiety drugs. Including alprazolam (Xanax), diazepam (Valium), and lorazepam (Ativan).
• Antiplatelet and anticoagulant drugs (blood thinners). Including clopidogrel (Plavix) and warfarin (Coumadin).
• Some cancer drugs. Including the breast cancer drug Raloxifene.
• Drugs broken down by the liver. Because milk thistle works on the liver, it may affect drugs broken down by the liver, of which there are many. Speak with your doctor.

Supporting Research

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