September 2021

· 4 min read

Risky Business: Beware of Banned Substances in Sports Supplements

If you are into athletics, it is up to you to evaluate the risk if you take sports supplements. Our expert helps you spot warning signs.
A man with sport nutrition products - Beware of Banned Substances in Sports Supplements | NSF

Whether you’re a weekend warrior or competitive athlete, you may be looking for supplements to lesson joint pain, boost your immunity or to build muscle mass.

“Be careful,” says John Travis, Technical Leader for NSF’s Certified for Sport® program.

“The dietary supplement industry is ever evolving and ever growing,” says John. “So many of us are taking vitamins and supplements and at the same time, the dietary supplement industry is loosely regulated in many regions. This means manufacturers don’t have to scientifically prove their products are safe for you to take nor do they have to prove what is listed on the label ends up in the bottle on the shelf. Because of this, if you take supplements, you can be at risk for products that are contaminated with harmful ingredients.”

What Is a Banned Substance?

An athletically-banned substance is a substance that has been prohibited for use by professional athletes as it may give the athlete an unfair physical advantage, such as enhancing strength or endurance, or it may cause health risks to the athlete.

According to a 2018 report by the World Anti-Doping Agency, 1,640 sports supplement samples were reported as anti-doping rule violations, confirmed to contain banned substances. However, everyday sports supplements can also contain unhealthy and illegal ingredients. For example, some protein supplements available at common retailors, intended for purchase by athletes seeking to build muscle or to gain weight, have been contaminated by illegal steroids.

Athletes Beware

Banned substances can put professional and collegiate athletes’ careers at risk, resulting in disqualification from competition. Many news stories have covered athletes who took over-the-counter supplements only to find out later that the products contained a substance not allowed by their sport.

What Can You Do?

“We’ve all seen vitamins and other supplements that claim to improve your athletic performance,” says John. “Any supplement promising to miraculously make you stronger or have greater endurance is probably one you should consider avoiding.”

“Be especially aware of supplements that promise dramatic gains in your ability over a short period,” he adds. “That may be a signal that the supplement you are using contains drug-like ingredients that could be harmful to your long-term health.”

We’ve all seen vitamins and other supplements that claim to improve your athletic performance.

More Info About Banned Substances

Some banned substances are intentionally added to supplements, while others may be naturally occurring. For example, boldione, is a naturally occurring anabolic androgenic steroid that has been found in plants such as Rhodiola rosea roots and guduchi vines.

Anabolic androgenic steroids (AAS), often synthetic or human-made variations of the male sex hormone testosterone, are common banned substances. “Anabolic” refers to muscle building and “androgenic” refers to increased male sex characteristics. Some people misuse these substances in an attempt to boost performance or improve their physical appearance. Manufacturing or selling these drugs is a felony. In addition, repeated or regular use of AAS can lead to kidney and liver damage, increased blood pressure and increased risks of stroke and heart attack. It may also promote the development of tumors.

So, Who Decides When a Substance Is Banned, and Why?

The World Anti-Doping Agency (WADA) and other leading athletic organizations, like the United States Anti-Doping Agency (USADA), Major League Baseball (MLB), the National Football League (NFL), the National Hockey League (NHL) and the Canadian Centre for Ethics in Sports (CCES), have developed lists of prohibited substances. These include substances that enhance or may enhance physical performance, introduce health risk to the athlete or otherwise violate the spirit of sport.

NSF recommends purchasing supplements that have been tested and certified by NSF or similar organizations not to contain banned substances. Currently, NSF tests sports supplements for more than 300 banned substances in our laboratories across the globe to minimize the risk of unintended doping for professional and non-professional athletes.

Certification also confirms that the ingredients and quantities reported on the product label are accurate, and that the product does not contain harmful levels of contaminants like heavy metals or pesticides.

What to Look for When Choosing supplements

John recommends the following:

  • Avoid supplements that claim to be substitutes to anabolic steroids, cause rapid weight loss, or claim to treat or cure a disease or other health condition
  • Avoid supplements that contain high levels of caffeine, green tea extract and other stimulants, as they may lead to restlessness, anxiety, racing heart or an irregular heartbeat, especially in teens
  • Do not mix supplements or take a supplement at a higher than recommended dose (like taking two scoops instead of one) as this may negatively affect health
  • Avoid supplements that contain contaminants or unapproved synthetic stimulants like N,a- DEPEA, DMAA, DMBA or oxilofrine, which may appear on product labels as ingredient names like geranium extract or 4-amino-2-methylpentane citrate
  • Purchase supplements that have been tested and certified to contain the reported active ingredients and no banned substances or other hazardous contaminants like heavy metals and pesticides at unsafe concentrations

Certified supplements are listed at and in the NSF for Sport app.

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