Herbal Adulteration: What are the concerns?

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Supplements and herbal fluid extracts are used every day in natural medicine clinics. We assume that everything that is printed on the label is in the bottle, and trust that all the ingredients are validated for purity and quality. Practitioners put their trust in suppliers that all necessary checks and measures have been passed at every step of manufacture.

But unfortunately, whether it be the natural medicine industry[1,2], petroleum products[3] or, most importantly, our food supply[4], the sad fact is that wherever commerce exists so does adulteration. 

As natural medicine professionals, we are mostly concerned about adulteration in the natural medicine arena. However, when it comes to foods, there have been cases of substitution of cereals and coffee husks for coffee,[5] and adulteration of olive oil by the addition of cheaper oils such as soybean oil, canola oil, sunflower oil, corn oil and hazelnut oil,[6,7] which serve as reminders for health practitioners to be aware of such possibilities when advising patients with food intolerances or allergies.

Why Does It Occur?

1. Economically motivated adulteration

Firstly, there is no doubt that substitution occurs because of financial gain. This is called economically motivated adulteration and is the deliberate substitution of a usually less expensive ingredient.[1] This is the most abhorrent type of adulteration because it shows a complete lack of regard for the end user, the patient often in dire need of the therapeutic actions of the ingredient.

A golden fleece
Goldenseal (Hydrastis canadensis) is known for its yellow colour, which is due to its berberine content. It is also an expensive herb to source because it is not easy to cultivate. By contrast, goldthread (Coptis chinensis) and Oregon grape (Mahonia aquifolium)[8] are berberine-containing herbs that are much easier to grow and so, have been used as adulterants. Although goldthread has a valuable place in herbal practice, it is, like Oregon grape, devoid of hydrastine, a constituent of goldenseal with separate antimicrobial effects.

2. Mistaken identity

Secondly, adulteration can occur from misidentification by lack of experience or inappropriate/invalid testing procedures. Although rare, this has in the past led to drastic consequences and lasting negative reverberations in our industry.

The killer weight loss tea -Aristolochia fangchi
In 1992, a popular Belgian weight loss product was withdrawn from the market after more than 100 cases of renal failure and urothelial carcinoma were caused by the substitution/adulteration of the herbal anti-inflammatory ingredient Stephania tetrandra (han fang ji) with the renotoxic herb Aristolochia fangchi (guang fang ji).[9] This catastrophic result occurred because of a seemingly simple mix-up in their common names.

In Australia, the Therapeutic Goods Administration (TGA) has identified 11 herbs that are vulnerable to adulteration by Aristolochia fangchi because of similar Chinese names or similar appearance.[10] Thankfully only four products in Australia have tested positive for aristolochic acids, necessitating an urgent recall,[10,11] the latest case taking place earlier this year when Shen Neng Herbal Medicines Group Pty Ltd were ordered to recall their Chuan Xiong Cha Tiao Wan pills. The unfortunate end-result of this example is that Stephania tetrandra, which has worthy anti-inflammatory actions, has been dropped from the repertoire of herbalists and naturopaths in Australia.

Relaxing skullcap leads to liver failure?
Between April 1997 and April 1998, 10 products in Australia containing Scutellaria lateriflora (skullcap), were recalled because of adulteration with an inferior species, S. incana, or germander (Teucrium spp.), a herb well known in the literature to cause liver toxicity. Consequently, the TGA took action to ensure samples and methods were made freely available to allow manufacturers to clarify the contents of their products.[12]

Kava damned by skullcap imposter?
In 2002, despite skullcap having been placed in the spotlight, an Australian product containing kava (Piper methysticum) and skullcap was implicated in the death of one patient from fulminant liver failure. Testing of the product revealed that it did not contain any skullcap. An adulterant was detected but has not been identified.[13]

Kava was instead singled out as the most likely cause. The resultant public scaremongering by those less informed and wishing to damage the herbal industry led to reduced consumer confidence in those who practice herbal medicine and the withdrawal of kava-containing products from the market.

Kava was finally allowed back on the Australian market two years later (only aqueous extracts are permitted),[14] however, the bad press still haunts kava today.

Echinacea identity crisis
Echinacea has had a long, troubled history of misidentification. Because of similarities in common names (Mississippi snake root vs. Kansas snake root), it was occasionally adulterated with Parthenium integrifolium. Such practice has largely been eradicated since the use of chemical markers to identify plant species.

However, in the 1990s, herbal products labelled as containing Echinacea angustifolia were found to actually contain E. pallida.[15] The major herbal and vitamin manufacturer had initially tested their products for echinacoside, which is present in both species, but results from later testing by more sensitive methods (TLC [thin layer chromatography] and HPLC [high performance liquid chromatography]) which are able to detect distinct differences in chemical constituents of echinacea species,16 forced the manufacturer to relabel its echinacea products.

3. The loophole

Lastly, the stringent testing and validation procedures imposed by the TGA extend only to those products, be they powder, liquid, tablet, or capsule, that are designated by law to be listed on the Australian Register of Therapeutic Goods (ARTG).[17] Powdered and liquid products that have been designated as foods fall outside this mandate, and are instead regulated by the relevant state or territory food authority.

The Pan Debacle

In April 2003, the TGA shut down Pan Pharmaceuticals and issued a nationwide recall on all products, pharmaceuticals and complementary medicine alike, manufactured by them. This was in response to identified discrepancies in doses per tablet of an ingredient in one of Pan’s drug formulations named Travacalm.[18]

Audits by the TGA on Pan Pharmaceuticals revealed critical manufacturing deficiencies including substitution of ingredients, manipulation of[10] test results and substandard manufacturing processes.[19]

In 2005 Pan pleaded guilty to 24 charges relating to defective medication and was fined $3 million for the offences. However, three years later, Jim Selim, founder of Pan, received $55 million for damages and legal costs after the TGA settled a civil action brought against it for acting negligently and outside the limits of its statutory powers when it issued the recall.[18]

Out of the Pan, into the light?
What is now known as “The Pan Debacle” or simply “Pan”, brought to light the many deficiencies in the “checks and measures” of our industry, which were intended to safeguard the public interest. 
Since 2003, legislative changes have been implemented to lift manufacturing in the nutritional/herbal industry to new heights of quantitative and qualitative procedures. Such amendments include the requirement for more extensive record-keeping and increased penalties,[20] to further strengthen the TGA’s stringent Good Manufacturing Practice (GMP) guidelines (see Table 1), which are now globally considered the gold standard for quality products manufacturing and safety assurance to the public.

The Ever-Present Threat
Even with gold standard manufacturing and quality assurance procedures in place, our vigilance should not wane, particularly in these competitive times when quality comes at a high price. In fact, reports are surfacing of poor quality herbs being “spiked” with chemical markers to give the perception of a higher quality, higher potency product. Table 2 presents some examples of spiking which have occurred recently.

Further research into qualitative aspects of herbs is required to detect and eradicate this practice. Until then, adulterated herbs will continue to plague manufacturers and the current market, whether from unscrupulous suppliers or a breakdown of mandatory procedures.

Bilberry bastardised
In 2006, the demand for bilberry (Vaccinium myrtillus) was increasing the world over but a poor harvest resulted in prices increasing 70%.[22]

By 2007, it was reported that bilberry extracts on the market were being adulterated with the cheaper mulberry or black bean skins, to the point where Japan, the largest market for the extract, was even considering banning the herb entirely.[22]

Relying on ultraviolet (UV) spectrometry to identify the herb is not sufficient to detect spiking with azo dyes which could imitate the deep blue colour reputed of bilberries. More sophisticated analyses such as HPLC, are better able to correctly detect the anthocyanin profile specific for bilberry.[22,23]

Pomegranate persecuted
Up until very recently, the accepted chemical marker for pomegranate had been ellagic acid. More recently however, a group from the University of California subjected pomegranate supplements to HPLC testing, which is sensitive to the signature constituents punicalin and punicalagins. They found less than 20% of the samples contained the signature constituents, and postulated that cheaper sources of ellagic acid such as chestnut bark, may have been used to adulterate the other supplements. Thus, using the previously accepted chemical marker for pomegranate is not a guarantee of authenticity.[24,25]

Beguiled by ginkgo?
Earlier this year, after claims of ginkgo (Ginkgo biloba) adulteration in Australia, the TGA surveyed 20 products and found one third to contain flavonoid compounds indicative of G. biloba in ratios that were not consistent with the expected chemical profile.[26] In other words, they were likely to be adulterated with quercetin and rutin to bump up the flavonol glycosides content.

The TGA stopped short of recalling or revealing these questionable products and instead enforced new guidelines for the testing of the authenticity of ginkgo extracts. From 18 January 2010, all new batches of ginkgo products are required to pass a quantitative analysis (content of flavonol glycosides) and qualitative analysis (ratio of quercetin, kaempferol and isorhamnetin).

Melamine masquerades as milk protein
In September 2008, a worldwide scare erupted involving the contamination of milk products with melamine, a toxic chemical used in the plastics and building industry. Nearly 300 000 infants suffered urinary problems such as kidney stones, and six babies died, after consuming melamine-tainted baby formula as well as other milk products. 

The contamination was later revealed to be a deliberate act of economically motivated adulteration whereby company executives allowed melamine to be added to watered down milk products to inflate the measured protein content.[27,28]


It’s important that all practitioners to be vigilant and confident in reporting adverse reactions in patients, and not to be concerned with drawing negative attention to our industry. The consequences of not reporting could be much worse. Practitioners should be confident in contacting their suppliers to determine the cause of an adverse event. It may be due to an unknown allergic reaction to a listed ingredient, a confounding factor, or perhaps, the first alert of a possible adulteration of a starting ingredient.


  1. Starling S. Economically motivated adulteration remains rife: CRN. NutraIngredients-USA.com. Decision News Media SAS, 2009 Aug 4. [Link
  2. Israelsen L. Spiking: is the end near? Nutraceuticals World 2009 Jun:57-58. [Link
  3. Haley J. Fuel guide. Open Road, NRMA. [Link
  4. McNally A. Fingerprints could help stop fake food. NutraIngredients.com. Decision News Media SAS, 2008 Jan 9. [Link
  5. Nogueira T, do Lago CL. Detection of adulterations in processed coffee with cereals and coffee husks using capillary zone electrophoresis. J Sep Sci 2009 Oct;32(20):3507-3511. [Abstract
  6. Arlorio M, Coisson JD, Bordiga M, et al. Olive oil adulterated with hazelnut oils: simulation to identify possible risks to allergic consumers. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2009 Sep 15:1-8. [Abstract
  7. Zou M, Zhang X, Qi X, et al. Rapid authentication of olive oil adulteration by Raman spectrometry. J Agric Food Chem 2009 Jul 22;57(14):6001-6006. [Abstract
  8. Brown PN, Roman MC. Determination of hydrastine and berberine in goldenseal raw materials, extracts, and dietary supplements by high-performance liquid chromatography with UV: collaborative study. J AOAC Int. 2008 Jul-Aug;91(4):694-701. [Full Text
  9. International Agency for Research on Cancer (IARC) Working Group on the Evaluation of Carcinogenic Risks to Humans. IARC monographs on the evaluation of carcinogenic risks to humans: some traditional herbal medicines, some mycotoxins, naphthalene and styrene, vol. 82. Lyon: IARC Press, 2002.
  10. Aristolochia fact sheet. Department of Health and Ageing, Therapeutic Goods Administration, 2001 May 25. [Link
  11. Consumer level medicine recall of Chuan Xiong Cha Tiao Wan. Department of Health and Ageing, Therapeutic Goods Administration, 2009 Apr 17. [Link
  12. Therapeutic Goods Administration. Submission to the Productivity Commission Review of Cost Recovery by Commonwealth Agencies, 2000 Dec 4.
  13. Information for sponsors: safety of kava-containing medicines. Department of Health and Ageing, Therapeutics Goods Administration, 2002 Aug 28. [Link
  14. Therapeutic Goods Regulations 1990, Schedule 4, Part 4, Division 2 (Plant material from which herbal substances may be derived for listable goods that are consistent with certain qualifications), Item 35. Canberra: Office of Legislative Drafting and Publishing, Attorney-General’s Department, 2007 Jul 1. [Link
  15. Rogers KL, Grice ID, Mitchell CJ, et al. High performance liquid chromatography determined alkamide levels in Australian-grown Echinacea spp. Aust J Exp Agric 1998;38(4):403-408. [Abstract
  16. Bauer R, Khan IA, Wagner H. TLC and HPLC analysis of Echinacea pallida and E. angustifolia roots1. Planta Med 1988 Oct;54(5):426-430. [Abstract
  17. Therapeutic Goods Administration. Australian regulatory guidelines for complementary medicines (ARGCM), 2005-2006.
  18. Timeline for Travacalm, Pan Pharmaceuticals and Jim Selim. The Daily Telegraph, 2008 Aug 14. [Link
  19. TGA reminds Australians of the potential danger of Pan Pharmaceuticals. Therapeutic Goods Administration, 2003 Aug 23. [Link
  20. Expert Committee on Complementary Medicines in the Health System. Complementary medicines in the Australian health system. Commonwealth of Australia, 2003 September.
  21. Wardle J. Regulation of complementary medicines: a brief report on the regulation and potential role of complementary medicines in Australia. East Brisbane: The Naturopathy Foundation, 2008. [Full Text
  22. Daniells S. Industry needs to wake up to adulterated bilberry extracts. NutraIngredients.com. Decision News Media SAS, 2007 May 14. [Link
  23. Penman KG, Halstead CW, Matthias A, De Voss JJ, Stuthe JM, Bone KM, et al. Bilberry adulteration using the food dye amaranth. J Agric Food Chem 2006 Sep 20:54(19):7378-7382. [Abstract
  24. Heller L. Study questions pomegranate supplement standardization. NutraIngredients-USA.com. Decision News Media SAS, 2009 Jul 31. [Link
  25. Zhang Y, Wang D, Lee R-p, Henning SM, Heber D.Absence of pomegranate ellagitannins in the majority of commercial pomegranate extracts: implications for standardization and quality control. J Agric Food 11 Chem 2009;57(16):7395-7400. [Abstract
  26. Composition of Ginkgo biloba products. Therapeutic Goods Administration, 2009 Oct 2. [Link
  27. Risk assessment and referral levels for dairy foods and foods containing dairy-based ingredients adulterated with melamine. Food Standards Australian New Zealand, 2008 Oct 14. [Link
  28. Vause J. Death sentences in China tainted milk case. CNN.com/asia, 2009 Jan 23. [Link


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andrew_whitfieldcook's picture
Andrew Whitfield-Cook

Andrew is a registered nurse of 32 years, with more than 20 years experience in the natural medicine industry. Andrew is curious about, well, everything! He delights in interviewing specialist clinicians and researchers about their work and how the practical use of nutritional and herbal medicines, and physical therapies, may improve patient health.
His interests include gastroenterology, immunology and oncology. Andrew has a deep responsibility to impart the efficacious use plus the relevant safety aspects of integrative medicine to natural medicine practitioners.