Over half of Americans take some sort of dietary supplement, according to the Food and Drug Administration (FDA). But they’ve long been controversial—do they help, hurt, or actually do nothing at all? And do supplements really contain what you think they do?
Sounds straightforward, but it might not actually be that simple: According to a new study from the JAMA Open Network, 776 different dietary supplements from 2007 to 2016 were shown to contain unapproved pharmaceutical ingredients that weren’t on their label.
Sexual enhancements, weight loss, and muscle-building supplements were among the most risky. Of the supplements shown to include unapproved ingredients, 46 percent were for sexual enhancement, 41 percent for weight loss, and 12 percent for muscle-building—the latter two which may be especially applicable for the active, running population.
“Twenty percent of the products had more than one unapproved ingredient,” study researcher Madhur Kumar, Ph.D., M.S, told Runner’s World by email. What’s more, 28 products were named in two or three FDA warnings about their unapproved ingredients.
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The common drug ingredients found in the weight loss supplements were sibutramine—an appetite suppressant that was taken off the market in 2010 after it was found to cause serious cardiovascular issues and liver damage—the laxative phenolphthalein, and the prescription antidepressant fluoxetine. Sibutramine, for instance, was detected in 85 percent of the weight loss supplements that were adulterated, and phenolphthalein in 24 percent.
In total, 25 percent of the adulterated weight loss supplements contained more than one hidden drug ingredient.
And muscle-building supplements also had some scary results, too. Of the 92 muscle-building supplements that were adulterated, 73 were deemed by the FDA to contain undeclared anabolic steroids or steroid-like substances.
“Overall, the study found that active pharmaceutical ingredients continue to be identified in dietary supplements, especially those marketed for sexual enhancement or weight loss, even after the prior public FDA warnings,” says Dr. Kumar. “The drug ingredients have the potential to cause serious adverse health effects due to misuse, overuse, or interaction with other medications, underlying health conditions, or other pharmaceuticals within the supplement.”
And another warning: If you’re ordering your supplements online, you should be extra careful. The study found that from 2014 to 2016, 39 percent of adulterated samples were identified through online sampling, and 34 percent were ID’ed through the examination of international mail shipments.
So how can you choose safe supplements? Honestly, it’s tricky. As the study noted, dietary supplements are not subject to premarket approval for safety and effectiveness by the FDA. That means the FDA is not authorized to review dietary supplements for safety and effectiveness before they are marketed—it’s up to the supplement manufacturers to make sure supplements are safe before they’re put on the market.
But doing your research can help. Seek information about the supplement you’re interested in from a non-commercial site, like the National Institute of Health’s (NIH) Office of Dietary Supplements, the FDA, and the United States Department of Agriculture.
The same goes for supplements with third-party verification seals like USP and NSF International. The seals don’t guarantee safety or effectiveness, but can be beneficial in ensuring the supplement contains the amount of ingredient stated on the label and isn’t adulterated with dangerous additives.
And consult your doctor before taking anything. As shown, the supplement you may want to take could contain pharmaceuticals or other ingredients that could interact negatively with medication you’re already taking, or make a condition you already have worse.