Investigators found that many store brand supplements do not contain what labels claim. Attorney General Eric Schneiderman from New York led the investigation, focusing on supplements branded by four major retailers to include Target, Wal-Mart, GNC, and Walgreens. After conducting DNA testing, it was discovered that just 21% of the products contained plant DNA as claimed on the labels.

As stated by Schneiderman, the investigation makes it perfectly clear that buyers really do need to beware, especially when it comes to herbal supplements. After testing was done, Schneiderman’s office issued cease and desist letters to all the retailers involved, advising to stop selling the products.

As part of testing, investigators found that ginseng, St. John’s wort, echinaccea, saw palmetto and ginkgo biloba were all contaminated with a variety of materials such as primrose, wild carrot, citrus, beans, pine, rice, houseplant, wheat, and asparagus. In the majority of cases, contaminants not listed were the only material from plants discovered in the product samples.

Of the different retailers investigated, the worst performing was Wal-Mart. For herbal supplements from this store, only 4% of tested included DNA from plants listed on the product labels. With new evidence of contamination, Schneiderman is requesting that all companies provide in-depth information specific to production, processing, testing, and quality control for herbal supplements sold.

According to Brian Nick, spokesman for Wal-Mart, the company has reached out to all pertinent suppliers and appropriate action will be taken. Both GNC and Walgreens also said they are 100% committed to working with the Attorney General. Spokesman James Graham with Walgreens said that these issues are taken seriously and as a precaution, involved products are being taken off shelves until the matter is cleared up.

Laura Brophy, spokeswoman for GNC did comment, saying that the company stands behind quality, potency, and purity of all ingredients listed for private label herbal supplements sold. When asked for comment Target did not respond.

DNA testing was conducted by James Schulte II who is a DNA barcoding technology expert with New York’s Clarkson University. However, president and CEO of the dietary supplement trade group, the Council for Responsible Nutrition, Steve Mister, criticized the procedure used for testing while accusing Schneiderman of pulling a self-serving publicity stunt while pretending to care about the protection of public health.

In a released statement, Mister said that the retailers should have been provided with a better opportunity to respond prior to Schneiderman taking the findings public. He also claimed that DNA can be eliminated or damaged during processing and manufacturing of herbal supplements so for these products, the type of DNA testing performed was wrong.

Even so, the US Food and Drug Administration (FDA) has a mandate whereby companies must validate their products as being safe and correctly labeled. The challenge is that unlike prescription medications, herbal supplements are not held to the same strict evaluation processes and because of this, most manufacturers rely on an honor system.