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Cancer Health Center

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Milk Thistle (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - Overview

This complementary and alternative medicine (CAM) information summary provides an overview of the use of milk thistle as a treatment and adjunct agent for people with cancer.

The summary includes a brief history of milk thistle, a review of the laboratory studies and clinical trials, and a description of adverse effects associated with milk thistle use.

Recommended Related to Cancer


Note: Separate PDQ summaries on Testicular Cancer Treatment and Levels of Evidence for Cancer Screening and Prevention Studies are also available. Benefits Based on fair evidence, screening for testicular cancer would not result in an appreciable decrease in mortality, in part because therapy at each stage is so effective. Magnitude of Effect: Fair evidence of no reduction in mortality. Study Design: Opinions of respected authorities based on clinical experience, descriptive...

Read the Overview article > >

This summary contains the following key information:

  • Milk thistle is a plant whose fruit and seeds have been used for more than 2,000 years as a treatment for liver and biliary disorders.
  • The active substance in milk thistle, silymarin, is a complex mixture of flavonolignans, primarily consisting of the following isomers: silybin (consisting of silybins A and B), isosilybin (consisting of isosilybins A and B), silychristin (also known as silichristin), and silydianin (also known as silidianin). In the literature, silybin is often referred to as silibinin.
  • Laboratory studies demonstrate that silymarin functions as an antioxidant, stabilizes cellular membranes, stimulates detoxification pathways, stimulates regeneration of liver tissue, inhibits the growth of certain cancer cell lines, exerts direct cytotoxic activity toward certain cancer cell lines, and may increase the efficacy of certain chemotherapy agents.
  • Human clinical trials have investigated milk thistle or silymarin primarily in individuals with hepatitis or cirrhosis.
  • Few adverse side effects have been reported for milk thistle, but little information about interactions with anticancer medications or other drugs is available.
  • Milk thistle is available in the United States as a dietary supplement.

Many of the medical and scientific terms used in the summary are hypertext linked (at first use in each section) to the NCI Dictionary of Cancer Terms, which is oriented toward nonexperts. When a linked term is clicked, a definition will appear in a separate window.

Reference citations in some PDQ CAM information summaries may include links to external Web sites that are operated by individuals or organizations for the purpose of marketing or advocating the use of specific treatments or products. These reference citations are included for informational purposes only. Their inclusion should not be viewed as an endorsement of the content of the Web sites, or of any treatment or product, by the PDQ Cancer CAM Editorial Board or the National Cancer Institute.

    This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

    WebMD Public Information from the National Cancer Institute

    Last Updated: 8/, 015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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