Dietary Supplements Found Tainted With Prescription Meds

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The Food and Drug Administration (FDA) found between 2007 and 2016 that 776 dietary supplements from 146 companies contained prescription drugs, some of which pose significant dangers to consumers.

Yet the FDA never issued any mandatory recalls. It announced voluntary recalls—when companies agree to pull products from store shelves—in less than half of those cases.

These findings, based on FDA data, were published Oct. 12 in the journal JAMA Network Open.

Some people turn to supplements thinking they are getting a safe, “natural” alternative to pharmaceuticals, says Chuck Bell, programs director for Consumers Union, the policy and mobilization division of Consumer Reports. “Clearly,” he says, “this is not always the case.”

Here’s what you need to know about the new study, supplement safety, and how the FDA has handled recalls.

The Risks of Contaminated Supplements

The researchers, from the California Department of Public Health, found that supplements marketed to help with erectile dysfunction, weight loss, or muscle building were the most likely to be adulterated with unapproved pharmaceutical ingredients.

These contaminants included sildenafil (Viagra and generic), fluoxetine (Prozac and generic), sibutramine (an appetite suppressant withdrawn from the market due to heart attack and stroke risks), and anabolic steroids—some of which have not been approved for human use.

The FDA does not publicly release the amounts of these ingredients found in each supplement, so it’s impossible to know exactly how dangerous the additions were. (The FDA also doesn't disclose how many and which types of supplements it tests each year, the study authors note.)

Manufacturers may be adding prescription drugs to supplements to increase their effectiveness, says Pieter Cohen, M.D., an associate professor of medicine at Harvard Medical School and staff physician at Cambridge Health Alliance whose editorial was published alongside the new study. Consumers who purchase an erectile dysfunction supplement with added Viagra, for example, may not realize what’s really behind the results.

“This is a really significant problem, with potentially devastating medical consequences,” says Bell. “Thousands of people visit the emergency room every year due to adverse effects from supplement use.”

In the past, the study authors note, the use of dietary supplements has been linked to adverse events, including stroke, acute liver injury, kidney failure, pulmonary embolisms, and death. One study found that dietary supplement use was associated with 23,000 emergency department visits in the United States each year.

Taking unprescribed pharmaceuticals can also create risky interactions with existing prescriptions. For example, taking sildenafil along with certain drugs that treat diabetes, high blood pressure, and high cholesterol can lower blood pressure to dangerous levels.

Companies that add pharmaceuticals to their products are “a stain” on the industry, says Duffy MacKay, N.D., the senior vice president of scientific and regulatory affairs at the Center for Responsible Nutrition (CRN), a trade association for the supplements industry. “We support vigorous prosecution of supplement companies that include unannounced drugs in their products.”

Why These Supplements Are Still Sold

The new study revealed not only that hundreds of supplements are contaminated with potentially dangerous prescription drugs, but also that in 52 percent of cases, companies did not recall supplements even with known adulterants. And there were zero cases where the FDA issued a mandatory recall, something the agency has been empowered to do since 2011.

The FDA told Consumer Reports in an emailed statement that it is "aware of the study and is in the process of reviewing and analyzing its findings." The agency also said that when supplements contain these types of unapproved pharmaceutical ingredients, they are generally excluded from the definition of a dietary supplement and may be subject to regulation as drugs—where the "FDA does not have mandatory recall authority."

“This study highlights some significant deficiencies in the FDA’s regulation of supplements,” says Cohen. “Whether it’s an issue of limited resources at the agency, or an unwillingness to pursue tough enforcement measures, there is a significant risk that is not being addressed.”

Voluntary recalls, which happened in 48 percent of cases in the new study, have also proven to be somewhat ineffective. Supplement recalls are often communicated to the public through FDA email alerts and postings on the agency’s website. But two recent studies indicated that supplements recalled due to pharmaceutical adulterants often continue to be sold, and many consumers remained unaware that the recalls even existed.

Supplement Safety

Americans spent about $42 billion on dietary supplements in 2017. But given the lax regulatory environment, it’s difficult to know exactly what you are getting when you take one, says Bell. Supplements also don’t undergo the same tests for safety and efficacy as prescription and over-the-counter drugs.

Here are three things you should do before you take a supplement.

  • Talk to your doctor. Your provider can make recommendations based on your complete medical history and risk factors, and also consider any potentially concerning interactions with your existing medications. Even supplements that are not contaminated can interact dangerously with certain drugs.

  • Look for a seal, such as “USP Verified” or “NSF.” These seals don’t indicate that a supplement works as advertised, but they do mean an independent group has vetted the quality or purity of the supplement to verify that it contains what it’s supposed to. (Read more about these seals and what they mean.)

  • Avoid the most dangerous supplements. Review our list of “15 Supplement Ingredients to Always Avoid,” and consider passing on supplements marketed to help with erectile dysfunction, weight loss, and muscle building, which this study found were the most likely to be contaminated with prescription drugs.

For more, see “4 Tips for the Smart and Safe Use of Alternative Medicine,” from our November 2018 cover story.

Editor's Note: This story was updated to include a response from the FDA, which CR received after the story's original publication.

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