Big mistake

What’s in your sports supplement? New paper warns of accidental doping

It is surprisingly common to unwittingly ingest hidden ingredients in sports supplements. Here’s what you need to know.

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In December 2018, Devin Logan, a freestyle skier and three-time Olympic gold medalist tested positive on a drug-screening test.

Logan had taken (permitted) cannabidiol (CBD) drops to help manage skiing’s brutal physical toll, but in doing so she inadvertently ingested enough of the cannabidiol THC to set alarm bells ringing. Natural and synthetic tetrahydrocannabinols (THC) are banned in her sport by the World Anti-Doping Agency.

The then 26-year-old Logan told reporters at the time that she was shocked when she tested positive. According to Logan and U.S. Ski and Snowboard CEO Tiger Shaw, the CBD supplement’s ingredient label claimed it had only trace quantities of THC. Logan completed a three-month suspension linked to the accidental doping case in 2019.

“I take 100 percent responsibility for it,” Logan told the Associated Press/Seattle Times in 2019. “Being a veteran of my sport, I should know better.”

Logan may personally believe she should have known better, but murky federal regulations and misleading labeling practices make determining the true ingredients of sports supplements near impossible.

It’s an athlete’s worst nightmare: A routine drug test comes back positive, revealing evidence of a banned substance in their system. Such a result can lead athletes to be barred from competing for months or years and even suspended from their sport. Some lose their past championship wins and medals. Yet, to their knowledge, they insist that they never consumed the steroid, drug, or banned substance in the first place. So how did the illicit substance in question ever end up in their system?

Supplements: Buyer beware

Italian cyclist Lorenzo Bernucci tested positive for banned substance sibutramine in 2007, leading his sponsor T-Mobile to sack him.

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Health professionals and exercise physiologists have sounded the alarm about unintentional doping and supplement contamination in sports supplements for years. New data, published in the journal BioMed Research International, suggests accidental doping is significantly more common than thought for both athletes and regular consumers.

In the new review article, scientists analyzed over 3,000 supplements investigated in 50 studies and found that approximately 28 percent contained “undeclared substances,” posing a risk of unintentional doping.

The most common sketchy substances that popped up were sibutramine, an appetite-suppressant often used for weight loss, and anabolic-androgenic steroids used to build muscles. Both these substances do more than heighten the risk of breaking doping rules. Anabolic steroids can disrupt the body’s natural hormone production, influence fertility, and cause cardiovascular problems. Sibutramine can cause heart problems, insomnia, and joint pain.

Athletes should be aware of this industry-wide contamination problem and take “great care” in choosing a dietary supplement, the review’s authors write.

How common is accidental doping? — When you think about doping, you might think of cyclist Lance Armstrong’s high-profile doping scandal, or the shockingly complex state-run doping scheme involving Russian athletes.

While such cases are premeditated, unintentional doping sneaks up on the athlete in question. The World Anti-Doping Association (WADA) doesn’t distinguish between intentional or unintentional doping, but the latter implies the athlete or consumer inadvertently ingested a banned or illegal substance.

And based on the most recent data, contaminated, banned, and illegal substances litter the supplement shelves. To map out a broader scope of the problem, scientists analyzed the data from over 50 studies published between 1996 and 2021 that tested the presence of contaminated substances in dietary supplements.

Out of the 3,132 supplements analyzed, 875 contained undeclared substances. Some 28 percent of the dietary supplements contained sibutramine, 26 percent contained testosterone and other anabolic steroids, and seven percent contained 1,3-dimethylamylamine (DMAA), which is a stimulant used for attention-deficit/hyperactive disorder (ADHD), weight loss, improving athletic performance, and bodybuilding.

The researchers also found 21 percent of the supplements analyzed contained an antidepressant and selective serotonin reuptake inhibitors (SSRIs) called fluoxetine. Various diuretics and Selective Androgen Receptor Modulators (SARMs) were also identified as undeclared substances in the dietary supplements at lower levels.

All in all, these potentially toxic substances were either not listed on the supplement bottle’s ingredient labels and in the dietary composition, or the amounts stated differed from the true content.

Most of the supplements analyzed in the study were purchased online or from local shops and pharmacies. Contaminated products originated all over the world, mostly from the U.S., the Netherlands, the U.K., Italy, and Germany, while some originated from China and Southeast Asian countries.

“No matter where a consumer lives, there is a chance to buy a contaminated dietary supplement,” the team says.

Sports supplements: Anyone’s game

Lance Armstrong was engulfed in a doping scandal for years following his successive, triumphant wins of the Tour de France.


An estimated 69 to 94 percent of elite athletes report taking dietary supplements regularly to fill nutritional gaps, boost performance, or recover from workouts and competition.

Many of these athletes, and most everyday consumers, think dietary supplements are similar to medication in that they are approved by government agencies, tested for safety and efficacy, and transparently disclose their ingredients. However, under current regulatory guidelines, manufacturers in the U.S. are not required to submit their supplements or products for government review or to prove their safety and efficacy in a clinical trial. Some companies voluntarily opt to conduct third-party testing on their products, but this is not the norm nor is it required.

When adverse events or complaints do lead a product to be banned in the United States, it often ends up back on the shelves with a new label. In 2014, researchers found that 67 percent of 27 tested dietary supplements banned by the Food & Drug Administration in the period from 2009 to 2012 were available on the market again a few years later in 2014.

A new approach — After facing scrutiny for years about its loose approach to regulating the massively profitable and popular dietary supplement industry, the FDA recently drafted guidance to bolster the safety information on “new dietary ingredients” (NDI), such as vitamins, minerals, and probiotics.

Based on current guidelines, manufacturers are technically responsible to submit their products for safety review if they have a new dietary ingredient — this is defined as an ingredient that was not marketed before the Dietary Supplement Health and Education Act (DSHEA) passed on October 15, 1994. But the FDA admits that many companies had skirted around that requirement, and didn’t submit data on a new ingredient before selling their product.

If the new guidance comes into effect, manufacturers will have 180 days to submit any late new dietary ingredient notifications. But even if a company complies, these notifications will likely be based on in-house, biased data stemming from company-sponsored studies, so their rigor and reliability aren’t entirely sound.

Before an athlete adds a new dietary supplement to their routine, doping experts and health professionals advise that the supplement should be tested for purity, quality, and safety in an accredited lab.

For those of us who consider ourselves at-home athletes, it’s essential to double-check that you are taking the highest-quality supplement possible to ensure you aren’t unwittingly doping yourself or putting your health in jeopardy.

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