An investigation into the efficacy of over-the-counter dietary supplements revealed the products did not even contain the herbs that were listed on the labels. This prompted the New York state attorney general's office to order four major retailers - Walgreens, Target, GNC and Wal-Mart - to yank their store-branded supplements from shelves.
The good news is most of what those products did contain was reportedly "filler," which is mostly to say the substances were generally harmless (beans, carrots, powdered rice, peas,etc.), though there were some that contained possible allergens not listed on the labels (peanuts and soybeans).
The bad news is, there is a strong potential that many other supplements from other brands remain on shelves without clear accountability of what is contained therein. Plus, these brands use carefully-worded promotional ads to tout uses that are unproven and unapproved. In some cases, they can be very harmful.