A new study finds that a high percentage of dietary supplements still contained banned drugs at least six months after being recalled by the U.S. Food and Drug Administration (FDA). Approximately half of all FDA class-I drug recalls since 2004 have involved dietary supplements adulterated with banned pharmaceutical ingredients. Previous studies have found that dietary supplements remain on store shelves even after FDA recalls, but a new study just published in the Journal of the American Medical Association (JAMA) found that 68 percent of the dietary supplements analyzed still contained the banned drugs at least six months after their recall. “Action by the FDA has not been completely effective in eliminating all potentially dangerous adulterated supplements from the US marketplace,” wrote Dr. Pieter A. Cohen of Harvard Medical School and his colleagues. “More aggressive enforcement of the law, changes to the law to increase the FDA’s enforcement powers, or both will be required if sales of these products are to be prevented in the future.” The products studied were recalled due to adulteration with pharmaceutical ingredients between Jan. 1, 2009, and Dec. 31, 2012, and available for purchase in July or August 2013. The supplement name, manufacturer, and distributor listed on the purchase also had to be identical to the information provided in the FDA recall. Researchers analyzed 27 of the 274 dietary supplements recalled by FDA in 2009-12 that met their criteria. They used the same methods FDA field laboratories do to screen for adulterants. Eighteen of the supplements contained a pharmaceutical adulterant. All but one of these had the same drug identified by FDA, and six of them had additional banned ingredients not identified by FDA. The banned substances included sibutramine, sibutramine analogs, sildenafil, fluoxetine, phenolphthalein, aromatase inhibitor, and various anabolic steroids. The researchers acknowledged certain limitations on their study — the main one being that although they made every effort to purchase recently manufactured supplements, “it is not known if all supplements were manufactured after the FDA recall.” Daniel Fabricant, director of FDA’s Division of Dietary Supplement Programs from 2011-14 and current CEO of the Natural Products Association (NPA), said that the implications of the study are “largely overblown.” He was particularly critical of the fact that only 27 substances were tested for the study. “I think this study aims to say there aren’t adequate laws on the books,” Fabricant said. But, in his three years with FDA, he said the agency showed this wasn’t the case. “I think we showed that the laws certainly work and have a lot of value to them.” He added that dealing with companies that continue to break the law calls for strong enforcement tools. Legitimate dietary supplements are regulated as a category of food, but products “masquerading as supplements” are treated as drugs within FDA. Fabricant believes it might be worthwhile to direct some of the food tools, such as administrative detention and mandatory recall authority available under the Food Safety Modernization Act, toward this issue. Fabricant’s message to consumers is that, “If product claims sound too good to be true, they likely are and that should be a red flag.” The JAMA-published study was supported, in part, by a grant from Consumers Union.