Most St. John’s Wort Supplements Fail Quality Tests

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Most St. John’s Wort Supplements Fail Quality Tests

As I report in my best-selling book, Alternative Medicine: The claims, the options, the evidence, how to choose wisely, St. John’s wort can be a safe and effective antidepressant herb for mild to moderate depression. But, as I warned in my book, and as yet another independent quality testing lab reports, heavy metal contamination and low potency are still concerns.
ConsumerLab reports, “St. John’s wort has been shown to be effective in treating mild to moderate forms of major depression.” But, the independent quality testing lab’s newest report found that only a few of the herbal supplement brands recently tested met quality standards.
Among the ten St. John’s wort supplements selected for testing, only four (40%) met’s quality standards. In other words, 60% of the brands tested FAILED quality testing.
Americans purchased $55 million of St. John’s wort supplements in 2008 according to the Nutrition Business Journal, down significantly from a high of $315 million in 1998. And, since natural medicines (herbs, vitamins, and supplements) are essentially unregulated in the U.S., consumers can have a difficult time finding product that is both safe and effective.
This is why I recommend to my patients, that before you invest your hard earned money in a natural medicine, spend a bit to get a quality testing labs results on the herb(s), vitamin(s), and/or supplement(s) you are considering. Single reviews of products by cost less than a bottle of most natural medications, and can help protect your from contaminated or mislabeled product.
With St. John’s wort this is particularly important, as the herb is known to naturally heavy metals from the soil. There are more details about the ConsumerLab results below, but if you’d like an evidence-based, best-selling review of alternative medicine (including the most popular alternative therapies and natural medicines used in the U.S.) consider:

  • Purchasing a copy of Alternative Medicine: The claims, the options, the evidence, how to choose wisely here.
  • You can view the Table of Contents here.
  • You can read the First Chapter here.

Now, here are more details from the report on St. John’s wort:
Four supplements (40% of those tested) failed testing due to contamination with cadmium, a heavy metal that can cause cancer and be a kidney toxin.
One of these four products (25%) was also contaminated with an amount of lead that, although small, would necessitate a warning label in the State of California if the company was required to test for it.
Three products (30% of those tested), including one of those contaminated with cadmium, contained only 22.6% to 36.2% of St. John’s wort plant chemicals (hypericin or hyperforin) expected from their labels.’s Product Review of St. John’s Wort Supplements is available here and includes results for thirteen supplements.
Ten were selected by and three others are included in the report for having passed the same evaluation through’s Voluntary Certification Program.
Also listed are two products similar to ones that passed but sold under different brand names.
Brands included in the report are CVS, FreeLife Depeze, Kira, L.A. Naturals, Nature’s Answer, Nature’s Bounty, Nature’s Sunshine, Nature’s Way, New Chapter, Puritan’s Pride, Rite Aid, Solaray, Standard Process, Vitamin Shoppe, and Vitamin World.  The report provides evaluations, ingredient comparisons, and expert tips on buying and using these supplements. is a leading provider of consumer information and independent evaluations of products that affect health and nutrition.
Reviews of St. John’s wort and many other popular types of herbs, vitamins, and supplements are available here.  Subscription to is available online.  The company is privately held and based in Westchester, New York.  It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products.
As readers of this blog know, I highly recommend ConsumerLab and use it almost daily in my office practice.


  1. Larry says:

    Great eye-opening post. I have used St. John’s Wart in the past and never even considered that it may be contaminated. I cannot find the test results though. When I click your link I am taken to a list of blog posts.

    • Dr. Walt says:

      Larry, thanks for the note and kind words. It is scary that these products are not regulated in the U.S. I just checked the links and they seemed to work, but just in case, I’ve reinstalled them. See if they work now. And, if not, try here or go here to the ConsumerLab website.

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