By David Kiefer, MD
Research Fellow,
Department of Family Medicine,
University of Wisconsin;
Clinical Assistant Professor of Medicine,
Arizona Center for Integrative Medicine,
University of Arizona

Dr. Kiefer reports no financial relationships relevant to this field of study.

Summary Point

  • Until sound testing methodology and retailer/government oversight is honed, clinicians and consumers should discuss the appropriateness of dietary supplement use and the choice of products from reputable companies.

This short report details an important series of events relevant to dietary supplement prescribing and purchasing. The controversy began in early February 2015, when the Attorney General of New York state sent cease and desist letters to Target, GNC, Walmart, and Walgreens after finding that four out of five supplements tested failed to contain any of the herbal medicines listed on the labels.1 The Attorney General’s office bought 78 bottles of leading brands from 12 stores across New York state, and then subjected the products to DNA barcoding analysis. DNA barcoding tests involve comparing extracts of a test sample to a library of known segments of DNA specific to a particular plant or animal.2,3,4 Such analysis is a relatively new science, but not new to controversy, as detailed in a past issue of Integrative Medicine Alert;5 certain extracts, purified phytochemicals, and/or tinctures would not be expected to contain DNA and, therefore, would be flagged in the testing, as done by the Attorney General’s office. Such concerns were voiced by industry and educational organizations such as the American Botanical Council.6

Despite the concerns over the scientific method, the four retailers cited by the Attorney General agreed to remove the products from the shelves of New York state stores. Walgreens even went so far as to remove the relevant products from its stores nationwide,7 and GNC announced plans to improve testing of its herbal medicines by using “advanced DNA testing” and allergen testing for tree nuts, soy, and wheat.8 The media fallout of this 2-month ordeal has played into the hands of dietary supplement critics, including academicians and politicians who have been quoted emphasizing safety and quality concerns of the dietary supplement industry; there are less stringent controls for dietary supplements (considered “foods” by the Food and Drug Administration) than for pharmaceuticals. It is less clear, however, what the correct approach should be for differentiating safe and quality products from their lesser cousins. Recent requirements that all dietary supplement companies adhere to Good Manufacturing Practices, as well as the presence of third-party testing organizations such as ConsumerLab and the United States Pharmacopoeia, have made some strides toward improvement in dietary supplement quality and safety. Until sound testing methodology and retailer/government oversight is honed, what remains crucially important is a dialogue between clinician and consumer about the appropriateness of dietary supplement use and the choice of products from reputable companies.


  1. O’Connor A. New York Attorney General Targets Supplements at Major Retailers. New York Times. Available at: Accessed April 3, 2015.
  2. Little DP, Jeanson ML. DNA barcode authentication of saw palmetto herbal dietary supplements. Sci Rep 2013;3:3518.
  3. Cimino M. Ensuring the specific identity and quality of herbal products by the power of DNA. HerbalGram 2010;86:50-57.
  4. Newmaster SG, et al. DNA barcoding detects contamination and substitution in North American herbal products. BMC Med 2013;11:222.
  5. Kiefer D. Herbal authenticity as per DNA barcoding in Canada. Integr Med Alert 2014;17:4-5.
  6. Smith T. A Review of the New York Attorney General’s Recent Actions against Herbal Dietary Supplements. HerbalEGram March 2015;12:3. Available at: Accessed April 3, 2015.
  7. O’Connor A. Chains Pull Dietary Aids Off Shelves After Inquiry. Available at: Accessed April 3, 2015.
  8. O’Connor A. GNC to Strengthen Supplement Quality Controls. New York Times. Available at Accessed April 3, 3014.