Widely Used "Adulterated" Supplements Not Regulated by FDA, Say Scientists

"Time and time again, they simply don't get the job done."


Supplements can contain a lot of substances, but one thing they shouldn’t contain are prescription drugs. Unfortunately, that’s not always the case. New research published Friday in JAMA Open Network shows that many widely available supplements contain unapproved pharmaceutical ingredients. This paper adds credence to earlier claims by scientists that not all supplements are what they say they are — regardless of what’s listed on the label.

Led by Jenna Tucker, M.P.H., a research scientist at the California Department of Food and Agriculture, the researchers behind the new paper scrutinize the most common types of drugs in the 776 “adulterated supplements” flagged in the FDA’s databases and examine the steps the FDA took to alert the public about them. To Pieter Cohen, Ph.D., an associate professor of medicine at Harvard Medical School who wrote an accompanying commentary, the results of this paper are just further confirmation of his belief that the FDA’s approach to regulating supplements is long overdue for a makeover.

“It’s been really frustrating to watch the FDA in action for the last ten years,” Cohen tells Inverse. “We’ve brought attention to issues by research — often research that confirms the FDA’s own pharmacists’ research. Time and time again, they simply don’t get the job done.”

For example, the FDA’s website notes that the administration regulates supplements as food, not drugs, and therefore doesn’t test supplements for safety and effectiveness in-house before they go to market. Though FDA officials do respond if public health complaints arise afterward, this means that sometimes supplements containing drugs slip through the cracks.

What Are The Most Common Hidden Ingredients?

Three different categories of supplements make up the bulk of the FDA’s tainted supplement database between 2007 and 2016. 48.5 percent of the total adulterated supplements were marketed for “sexual enhancement,” and of those, the study’s authors found that 47 percent of them contained sildenafil — the erectile dysfunction drug sold under the brand name Viagra. In short, people taking these sexual enhancement supplements (unnamed in the paper) were taking the active ingredient in Viagra without their knowledge.

These are the most common types of supplements in the FDA's adulterated supplements database.

JAMA Open Network

Weight loss supplements were the second most common category in the dataset — making up 40.9 percent of entries. In this case, researchers found that nearly half of these supplements contained sibutramine, which used to be sold under the brand name Meridia. Sibutramine is an appetite suppressant that was prescribed to help combat obesity until 2010, when it was found to be associated with an increased risk of stroke. Now, it’s a Schedule IV controlled substance, meaning that it has medical uses, but also a small risk of dependency and abuse.

Lastly, the paper shows that 11.9 percent of the adulterated supplements were intended for muscle-building pre- or post-workout They tended to include different types of anabolic steroids — which are basically synthetic versions of testosterone. Notably, this paper found that the majority of tainted steroid supplements were identified by the FDA between 2009 and 2010.

How Do The Ingredients Get In There?

Cohen explains that there are a few reasons that these ingredients end up in supplements. Namely, he says drugs are more potent than natural ingredient when it comes to things like increasing sexual function or weight loss.

“There’s very little legal ingredients that you can place in supplements that will help you lose weight or help improve your workout,” he says. “Therefore there’s a temptation to put something in there, like a drug, that will actually give the advertised effects. So if you’re selling a supplement that will help you lose weight, it’s easy to say, ‘Hey! why don’t we use this weight loss medication? Put it in there and then our consumers will lose weight.’”

But Cohen also adds that sometimes the supplement company itself may not even know where along the production line those ingredients were added — especially when pills and powders are manufactured abroad. In some cases, in an effort to cut costs, an ingredient supplier might slip in a synthetic drug as opposed to a more expensive, natural ingredient. Though he adds that the law requires companies to do testing to confirm that the supplement actually contains what it’s supposed to.

“We’re talking about big vats of powder that are being shipped in from China, let’s say, and they’re getting passed through multiple different hands before they’re getting to the company that’s labeling the bottle,” he says. In that sense, it can be hard for supplement makers to know that they’re receiving tainted products. “Now, with that said, the law says that everyone is responsible for the contents of what’s in it.”

What Can The FDA Do About It?

When the FDA finds out that a supplement has some extra additives, it can employ a few weapons in its arsenal. For one, FDA officials can issue a voluntary recall. This is what the FDA does in cases of food-contamination, but it was also the action taken for a mere 46.4 percent of the adulterated supplements analyzed in this study. This means that the company can choose to recall the product or not, but the FDA takes responsibility for overseeing their recall strategy.

The FDA issued recalls in less than half of adulterated supplement cases. 


Additionally, the FDA can issue a public notification — which it did in 44.1 percent of the cases this paper examined — or issue a news release, which it did in less than 1 percent of these cases. That aside, all cases of adulterated supplements are catalogued on the FDA’s website, which is where the paper’s authors found this data to start with.

In an emailed statement to Inverse, the FDA responded to this study’s results, stating that once they discover an adulterated supplement they work to inform the public and “remove it from market as soon as possible.” But they also highlight that adulterated supplements are hard to track down for a number of reasons:

Even after recall and enforcement action against one distributor, a number of other distributors of a product may continue to sell it. In addition, we have found that distributors often re-label products to evade detection. Distribution of these products can be lucrative for unscrupulous companies, and the agency faces several challenges in deterring fraudulent marketing of these types of products.

This paper is intended to illustrate that when it comes to regulating supplements, the process a slow-moving back-and-forth between companies and the FDA that happens only after people have taken tainted supplements and reported them. These authors and Cohen are calling for faster action and louder announcements when adulterated supplements are identified.

“We appreciate that the FDA often wants to do their own confirmatory tests before they move on something. My colleagues and I are trying to be as collaborative as possible with the FDA,” Cohen says. “But it takes getting a story into prominent media to get the FDA to act. And that’s not a way to ensure the safety of products that are consumed by half the population.”

An Excerpt of the Study Abstract
Importance Over half of adults in the United States report consuming dietary supplements. The US Food and Drug Administration (FDA) has warned of numerous dietary supplements containing undeclared, unapproved pharmaceutical ingredients. These FDA warnings have not been comprehensively analyzed for recent years.

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