A Double-take on Herbal Adulteration

As an herbalist who works in the herbal product industry, I care about quality and adulteration in herbal trade. But what happened earlier this week just bugs me. Issues of herbal adulteration are good reasons to use local herbs and develop relationships with suppliers. My problem with this is that adulteration is not even confirmed in this case–it’s findings from only one lab, using methods that aren’t even considered acceptable for validation of herbal extracts.

James Schulte was commissioned to perform DNA barcoding on supplements from 4 retailers across NY state. The samples were sent to one lab and many failed DNA testing, leading to conclusions of herbal adulteration. The New York Attorney General subsequently issued cease and desist letters to Walmart, Target, GNC, and Walgreens to remove herbal products from their shelves that failed DNA authentication.

This is another sad case of untrained people using inappropriate methods and firehosing their accusations across the media.

Problem #1: DNA validation only works on raw herb material, not extracts.

DNA testing requires intact genetic material. If herbs have been extracted or heat treated, DNA testing is not suitable. Even UV light used in sterilization can degrade DNA. No CGMP compliant company would use only DNA–even the FDA and USP would not accept it as a sole validation method. TLC fingerprinting is more acceptable.

Problem #2: James Schulte is a evolutionary biologist, not an analytical chemist or botanist.

He specializes in DNA testing of dinosaurs and lizards, but is untrained in natural products analytics. This is obviously a problem. There were no mentioned of microscopy, TLC, chemical or other analytics accepted by CGMP standards.

Problem #3: Only one lab was used, making the findings only preliminary.

It’s customary to confirm the findings of one lab with another. In this “study”, only one analytical lab was solicited. And it was not one recognized as an authority in the industry. Findings from one lab are preliminary and not actionable. It should have been a reason to perform further testing to obtain actionable results.

(See the New York Times and Washington Post articles, which are disappointingly characteristic of one-sided media coverage of the herbal industry. NutraIngredients USA has a thorough rebuttal.)

About Author

Renée A. Davis MA RH is a designer and educator in botanical and mycological medicine. Her training began at the Pratt Institute of Art and Design in New York City and concluded in biomedical sciences at the University of Washington. She currently directs research and development for a nutraceutical mushroom company in the Pacific Northwest.


  • Clara
    February 5, 2015 at 9:58 pm

    Brilliantly articulated Renee…very interesting to see what wave that article is creating over there!

  • Lauren
    February 6, 2015 at 7:25 pm

    Thank you for this!

  • Kendal
    February 11, 2015 at 7:16 pm

    Finally some clarity, thank you. As a NY health food store owner that prefers local herbalist preparations over conventional supplements, I shake my head at this, as well as the onslaught of inciting and reactionary emails filling my inbox from the Natural Products Association. Which while beating the drum for phone and email action, left me confused over the whole incident.

    “This is another sad case of untrained people using inappropriate methods and firehosing their accusations across the media.”

    Well said. Thank you again.


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