Washington, D.C.—FDAwarning lettersare falling short when it comes to deterring bad actors from selling dietary supplements adulterated with novel and unapproved stimulants linked to serious health risks. That's according to a new report

publishedin the Journal of the American Medical Association(JAMA; vol. 328, no. 4).

Pieter A. Cohen, M.D., of Cambridge Health Alliance, is the lead author of Recalls, Availability, and Content of Dietary Supplements Following FDA Warning Letters. His team set out to assess the frequency of product recalls and the presence of FDA-prohibited drugs in supplements after receiving FDA warning letters.

Findings on adulterated supplements & warning letters:

Dr. Cohen and team reported that FDA sent warning letters targeting the presence of BMPEA, methylsynephrine, or DMHA in 31 supplement products. Of these 31 products:

1 (3%) was recalled by the manufacturer.
9 (29%) remained available for purchase online a mean of six years after the FDA issued warning letters.
4 of those 9 available products (44%) listed the presence of at least 1 prohibited ingredient on the label. One product label declared the same prohibited ingredient that prompted the warning letter; the other three labels declared other FDA-prohibited ingredients.
The researchers also conducted chemical analysis, and found 5 of the 9 products (56%) contain at least 1 FDA-prohibited ingredient (see results here).

The authors acknowledged the study's limitations, including that the sample size was small and only 1 sample of each supplement was analyzed.

Dr. Cohen and team concluded: "This study raises questions regarding the FDA’s actions to ensure that manufacturers are compliant with the agency’s warning letters. The FDA should consider ways to ensure that prohibited drugs are removed from supplements, perhaps by testing products sold after warning letters and mandating recalls whenever products remain adulterated."

The Council for Responsible Nutrition responds

Megan Olsen,CRNSenior Vice President and General Counsel, said, “CRN applauds Dr. Cohen for keeping FDA accountable. It is unfortunately the case that the agency is not doing its job when one can find the same rogue ingredients in the same bad products six years after warning letters have been issued.

“This study demonstrates that warning letters alone are not viewed as sufficient threats by bad actors and outliers. FDA should stop assuming that everyone in the market wants to do the right thing. Unfortunately, it is the reality that there are bad guys out there who simply don’t.

“FDA’s enforcement must have consequences. The perceived risk to bad actors must be greater than the gains possible by flouting the law.

“FDA has recently been asking for new so-called ‘prohibited acts’ authority to clean up the industry. In other words, FDA wants clear-cut ability to address illicit substances that have never been marketed as drugs, nor even studied for their potential effects, but are nevertheless marketed as supplements.

“CRN supports giving FDA this authority and believes it will allow FDA to go after illicit substances not implicated by the ‘drug preclusion’ clause. These illicit substances may be currently caught in a legal no-man’s land—not supplements, not drugs, and without this new authority, not clearly within FDA’s enforcement. This simple change to the law—currently part of the Senate HELP committee’s user fee legislation—would give FDA capacity that much of the industry believes it already has but FDA has been requesting explicit statutory language to clarify.

“With this authority explicitly stated in the law, FDA can—and must—go after the bad actors that are the subjects of these research exercises over and over again.”