Over 20 percent of these offending products contained more than one unapproved drug ingredient, and numerous contained a cocktail of clandestine chemicals - in two cases, as many as six unlisted ingredients.
So, what did the FDA do about these supplements?
Being tainted or adulterated means that the product contains active ingredients not listed on the label that fly under the FDA's radar. Most of the tainted supplements were marketed for sexual enhancement, muscle building or weight loss, and the ingredients found in them were often pharmaceutical drugs - such as steroids or the active ingredient in Viagra - that consumers normally need a prescription to take.
"The drug ingredients in these dietary supplements have the potential to cause serious adverse health effects owing to accidental misuse, overuse, or interaction with other medications, underlying health conditions, or other pharmaceuticals within the supplement", researchers from the California Department of Food and Agriculture, Sacramento, explain in their paper. Unlike drugs, which are regulated by the FDA, the 1994 Dietary Supplement Health and Education Act classifies dietary supplements as food and are therefore not required to be subjected to the same testing by the agency.
Almost 800 dietary supplements sold over the counter from 2007 through 2016 contained unapproved drug ingredients, a new analysis of US Food and Drug Administration (FDA) data found. Numerous adulterated muscle building products contained undeclared anabolic steroids, which, when abused, can lead to mental problems in the short term and kidney problems, liver damage and heart problems in the long term. Of the 776 adulterated supplements identified, the FDA requested a voluntary recall of fewer than half (46.4 percent).
A different study found earlier that dietary supplement use was associated with 23 000 emergency department visits and 2000 hospitalizations in the United States each year.
Cohen also said the FDA should make changes to address the situation. Even more disturbing, in 2015 and 2016, about 85% of adulterated supplements received only public notifications, and only 15% were voluntarily recalled. Why the FDA has not done more to get these products removed from the market is being questioned. Of these products, 19 (67.9%) were reported to contain new unapproved ingredients in the second or third warning, consistent with the assumption that the FDA found the product to be adulterated a couple of times. Such products pose serious health risks, especially to users who are unaware that the supplements they are taking are actually adulterated with drugs. The FDA has also found that distributors often re-label products to evade detection.
"The agency's failure to aggressively use all available tools to remove pharmaceutically adulterated supplements from commerce leaves consumers' health at risk", writes general internist Pieter Cohen from Harvard Medical School in a commentary on the new research.