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Nonprofit Consortium Publishes Review of Skullcap Adulteration

Article Notes History of Confusion of Skullcap with Germander

(Austin, Texas. February 21, 2012) The substitution and adulteration of skullcap with germander is a challenge that has plagued the herb industry in the United States and elsewhere for over 30 years, and the problem still persists today, according to an article in the Winter 2012 issue of HerbalGram (#93), which has just been released.1 

In the article, noted botanist, author, and photographer Steven Foster traces the roots of common skullcap (Scutellaria lateriflora) adulterants, which can include inferior-grade, mislabeled, and, occasionally, potentially toxic substances. He continues with a discussion of modern cases of skullcap adulteration and suggests methods of verifying the herb's authenticity. 

In a 2011 study featured in Analytical and Bioanalytical Chemistry, researchers at USDA's Food Composition and Methods Development Laboratory at the Beltsville Human Nutrition Research Center in Maryland found that of 13 skullcap-containing dietary supplements tested, all of which were purchased through the Internet, only 5 had a measurable amount of true skullcap.2 Four supplements contained potentially toxic American germander (Teucrium canadense)—also sometimes known as wild germander, wood sage, and wild basil—which has been a known adulterant of skullcap products since the 1980s. Three supplements contained very low concentrations of skullcap and one sample contained Chinese skullcap, Scutellaria baicalensis, rather than the American species (S. lateriflora). 

Skullcap (also spelled "scullcap")—which has been used for centuries as a mild sedative and so-called "nerve tonic"—received international attention in the 1990s when some herbal products that claimed to contain it were associated with several cases of liver dysfunction. Analyses later revealed the source of toxicity to be European germander (Teucrium chamaedrys), another known skullcap adulterant. 

Foster had previously written a short, non-bylined article in HerbalGram in 1985 alerting members of the industry about the skullcap-germander substitution problem.3 In his new article, he describes a scientific paper from 1992 that first established germander as the source of harm. 

"A clear chronological relationship was established between ingestion of germander and the onset of hepatitis," Foster wrote. "Liver dysfunction was reversed after use of germander products was discontinued."

"In 2010 and 2011, I gave about a dozen speeches about adulteration problems in the global herb market, and I referred to the skullcap-germander problem as an example of a former problem," said ABC Founder and Executive Director Mark Blumenthal. "However, I was disappointed to read the report from the USDA scientists this past summer showing that skullcap is still being adulterated with germander!"

There are those who believe that skullcap and germander may look similar, since they are both members of the mint family (Lamiaceae or Labiatae). Foster, and various herbal experts, believe that their physical characteristics are distinct enough to warrant an accurate identification with the naked eye, i.e., in the field. 

According to an extensive quality control and therapeutic monograph on skullcap ("Skullcap Aerial Parts, Scutellaria lateriflora L.") produced by the nonprofit American Herbal Pharmacopoeia (AHP), the relatively comparable appearances of skullcap and other herbs can lead to accidental adulteration.4 The AHP monograph states, "Skullcap has historically been adulterated with various species of the potential hepatotoxic germander (Teucrium canadense, T. chamaedrys) due to morphological similarity between S. lateriflora and T. canadense." 

Foster recommends using the AHP monograph as a guide for properly identifying skullcap and germander species. "The most comprehensive and detailed information source on the topic is the 2009 AHP skullcap monograph which includes exhaustive information, illustrations, photographic images, and chromatograms on authentication, morphological difference, and chemical differences … of S. lateriflora, with an extensive discussion of adulterants." 

The HerbalGram article contains some line drawings from the Missouri Botanical Garden (MBG) on parts of skullcap and germander to help distinguish them, as well as author Foster's beautiful 4-color photography of both plants. The drawings are taken from a book on botanical identification produced by MBG and ABC.5 

The proper identification of herbal ingredients is paramount in helping prevent adulteration and protecting consumers. As Foster concludes, "Persistent, long-standing instances of adulteration and mislabeling of improperly identified botanicals, such as in the instance of skullcap adulteration with T. canadense, must be resolved to ensure that consumers get the herbal products they expect." 

"In our view, all manufacturers of herbal dietary supplements and herbal teas, in the U.S. and globally, should read this article and the AHP monograph on skullcap to ensure that they are taking adequate measures to confirm that their skullcap raw material has not been confused with germander," said ABC's Blumenthal. 

Foster's article is the second in a series of publications to come from the ABC-AHP-NCNPR (National Center of Natural Products Research) Botanical Adulterants Program, a nonprofit educational consortium that includes numerous third-party analytical laboratories and experts on herbs and herbal quality control. The program is preparing a technical laboratory guide to skullcap-germander adulteration, as well as a variety of review and technical publications on the adulteration of other herbs, herbal extracts, and essential oils. The ABC-AHP-NCNPR Botanical Adulterants Program is an industry-sponsored, self-regulated, educational initiative designed to help members of the global herbal supply and finished products community obtain increased access to information that can help ensure the accurate identity and quality of plant-based ingredients and products. The ABC-AHP-NCNPR Botanical Adulterants Program is supported and endorsed by over 60 companies and dietary supplement-related trade associations (see below).  

ABC-AHP-NCNPR Botanical Adulterants Program Supporters*(as of February 2012)

AdvoCare International, L.P.Amin Talati, LLCAmway/Nutrilite Health InstituteAveda CorporationBI NutraceuticalsCepham, Inc.Chemi NutraConsumer Healthcare Products   AssociationCouncil for Responsible NutritionDr. Bronner's Magic SoapsEnzymatic Therapy, Inc.Ethical Naturals, Inc.EuroPharmaEuromedEu Yan Sang InternationalFlavex Naturextrakte GmbHGencor Nutrients, Inc.Gaia HerbsGNC, Inc.Herbalife International, Inc.Horphag ResearchIndena USA, Inc.Law Office of Holly Bayne, P.C.Markan Global Enterprises, Inc.Martin Bauer, Inc.Metabolic Maintenance ProductsNatural Factors Nutritional Products,       Inc./Bioclinic NaturalsNatural Products Association Nature's Sunshine ProductsNature's Way

Naturex, Inc.NBTY, Inc.New Chapter, Inc.The New Frontier Foundation Fund of the    Greater Cedar Rapids Community FoundationNingbo Greenhealth Pharmaceutical Co, Ltd.Novel IngredientsNOW FoodsNSF InternationalNu Skin Enterprises/PharmanexNutivaNutra CanadaNutraceutical CorpNutritional Laboratories InternationalParagon LaboratoriesPerrigo CompanyPharmavite, LLCRainbow Light Nutritional SystemsRFI Ingredients, LLCSabinsa CorporationSchwabe North AmericaStandard Process, Inc.Thorne Research, Inc.Traditional Medicinals, Inc.United Natural Products AllianceValensa InternationalV.D.F. FutureCeuticalsVerdure SciencesVirgo PublishingWeil Lifestyle, LLCWhole Foods MarketZMC-USA

















*By acknowledging the generous support of these companies and organizations, ABC, AHP, and NCNPR are not endorsing any ingredients or products that may be produced or marketed by them.


1. Foster S. The adulteration of skullcap (Scutellaria lateriflora) with American germander (Teucrium canadense). HerbalGram. 2012:93;34-41. Available here.2. Sun J, Chen P. A flow-injection mass spectrometry fingerprinting method for authentication and quality assessment of Scutellaria lateriflora-based dietary supplements. Analytical and Bioanalytical Chemistry. 2011;401(5):1577-84.3. Foster S. Scullcap substitution. HerbalGram. 1985:2(3);3.4. Upton R, ed. American Herbal Pharmacopoeia and Therapeutic Compendium: Skullcap Aerial Parts. Scotts Valley, CA: American Herbal Pharmacopoeia; 2009.5. Applequist W. The Identification of Medicinal Plants: A Handbook of the Morphology of Botanicals in Commerce. Austin, TX, and St. Louis, MO: American Botanical Council and Missouri Botanical Garden Press; 2006.

About the ABC-AHP-NCNPR Botanical Adulterants ProgramThe ABC-AHP-NCNPR Botanical Adulterants Program is a consortium of independent nonprofit organizations whose mission relates to education, scientific research, and quality of botanical dietary ingredients and related plant-derived materials. The consortium is endorsed and supported by over 60 companies, law firms, and trade associations involved in the production, supply, manufacture, distribution, and marketing of herbal dietary ingredients and supplements.About the American Herbal Pharmacopoeia (AHP)About the National Center for Natural Products ResearchThe National Center for Natural Products Research (NCNPR) at the School of Pharmacy, University of Mississippi, is a unique university-affiliated research center devoted to the study of natural products and the realization of their benefits in human health, agriculture, and other applications. The NCNPR is recognized as a Center of Excellence for botanical supplements by the FDA's Center for Food Safety and Applied Nutrition.