[Paleopsych] Quack Watch: St. John's Wort

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St. John's Wort

[Following the Better Humans article, here's one from a professional 
debunking group. I wonder who finances them.]

                            Stephen Barrett, M.D.

    St. John's wort (Hypericum perforatum) has been widely claimed to be
    effective as an antidepressant. The mechanism of action is unknown;
    and the active ingredient, if any, has not been ascertained [1].
    Studies of extracts standardized for hypericin (one of the herb's
    constituents) have found it to be about twice as effective as a
    placebo. A few studies have found it somewhat more effective than a
    standard antidepressant. However, none of these studies lasted more
    than six weeks, which is not long enough to determine how long the
    herb would be effective or to detect any long-term adverse effects
    [2]. In addition, some of the studies were not well-designed [3,4]. In
    most of these studies, the diagnosis was not well established, the
    placebo response rate was lower than usually seen in such studies, the
    dosage of standard antidepressants was low, and the dosage of
    hypericin varied more than six-fold. [1]. No serious side effects were
    reported, but minor side effects include gastrointestinal discomfort,
    fatigue, dry mouth, dizziness, skin rash, and hypersensitivity to
    sunlight. However, in February 2000, British journal Lancet carried
    reports that St. John's wort could interfere with the effectiveness of
    an AIDS remedy (indinavir) [5]; an immunosuppressive drug
    (cyclosporin) used to protect patients after heart transplantation
    [6]; and an anticoagulant (warfarin) [7]. Based on this study and
    other reports in the medical literature, the FDA issued a Public
    Health Advisory stating:

      St. John's wort appears to be an inducer of an important metabolic
      pathway, cytochrome P450. As many prescription drugs used to treat
      conditions such as heart disease, depression, seizures, certain
      cancers or to prevent conditions such as transplant rejection or
      pregnancy (oral contraceptives) are metabolized via this pathway,
      health care providers should alert patients about these potential
      drug interactions to prevent loss of therapeutic effect of any drug
      metabolized via the cytochrome P450 pathway [8].

    St. John's wort should not be used by women who are pregnant or are
    breastfeeding. Nor should it be used together with standard
    antidepressants. The potency and purity of the preparations sold in
    the United States are unknown [1].

    There is no published evidence that St. John's wort is effective
    against severe depression, which, in any case, should receive
    professional help. For mild depression, psychotherapy directed at
    resolving the cause of the depression might be more prudent.

    The NIH Office of Alternative Medicine has funded a 3-year,
    $4.3-million [3]clinical trial that will compare the effects of
    hypericum, a placebo, and a standard antidepressive drug on patients
    who are followed for up to six months [9]. The results are expected in
    the year 2002. Regardless of the outcome, however, another problem
    must be overcome before consumers could use St. John's wort
    effectively. A Good Housekeeping Institute analysis of six widely
    available St. John's wort supplement capsules and four liquid extracts
    revealed a lack of consistency of the suspected active ingredients,
    hypericin and pseudohypericin. The study found:
      * A 17-fold difference between the capsules containing the smallest
        amount of hypericin and those containing the largest amount, based
        on manufacturer's maximum recommended dosage.
      * A 13-fold difference in pseudohypericin in the capsules.
      * A 7-to-8-fold differential from the highest to the lowest levels
        of liquid extracts [10].

    A sinilar investigation by the Los Angeles Times found that 7 of10
    products contained between 75% and 135% of the labeled hypericin
    level, and three contained no more than about half the labeled potency


     1. St. John's Wort. The Medical Letter 39:107-108, 1997.
     2. Linde K and others. [4]St. John's wort for depression -- an
        overview and meta-analysis of randomised clinical trials. British
        Medical Journal 313:253-258, 1996.
     3. De Smet PAGM, Nolen WA. [5]St. John's wort as an antidepressant:
        Longer term studies are needed before it can be recommended in
        major depression. British Medical Journal 313:241-242, 1996.
     4. Gaster B, Holroyd J. [6]St. John's wort in depression. Archives of
        Internal Medicine 160:152-156, 2000.
     5. Piscitelli SC and others. [7]Indinavir concentrations and St
        John's wort. Lancet 355:547, 2000.
     6. Ruschitzka F and others. [8]Acute heart transplant rejection due
        to Saint John's wort. Lancet 355:548, 2000.
     7. Jobst KA and others. Safety of St John's wort. Lancet 355:576,
     8. Lumpkin MM, Alpert S. [9]Risk of drug interactions with St. John's
        wort and indinavir and other drugs. FDA Health Advisory, Feb 10,
     9. St. John's wort study launched. Complementary and Alternative
        Medicine at the NIH 4(4):5, October 1997.
    10. Good Housekeeping Institute. New Good Housekeeping Institute study
        finds drastic discrepancy in potencies of popular herbal
        supplement. News release, Consumer Safety Symposium on Dietary
        Supplements and Herbs, New York City, March 3, 1998.
    11. Monmaney T. Labels' potency claims often inaccurate, analysis
        finds. Spot check of products finds widely varying levels of key
        ingredient. But some firms object to testing method and defend
        their brands' quality. Los Angeles Times, Aug 31, 1998.

                 This article was revised on April 16, 2000.


    1. http://www.quackwatch.org/04ConsumerEducation/QA/qa.html
    2. http://www.quackwatch.org/index.html
    3. http://www.the-scientist.library.upenn.edu/yr1999/feb/bunk_p10_990201.html
    4. http://www.bmj.com/cgi/content/full/313/7052/253?view=full&pmid=8704532
    5. http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?http://www.bmj.com/cgi/pmidlookup?view=full&pmid=8704522
    6. http://archinte.ama-assn.org/issues/v160n2/full/ira81029.html
    7. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10683007&dopt=Abstract
    8. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10683008&dopt=Abstract
    9. http://www.fda.gov/cder/drug/advisory/stjwort.htm
   10. http://www.quackwatch.org/04ConsumerEducation/QA/qa.html
   11. http://www.quackwatch.org/index.html

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