WWII-Era Stimulant Shows Up in Dietary Supplements on Store Shelves Today

Scientists from NSF and Harvard Medical School are warning consumers about a potentially harmful stimulant – deterenol – in supplements, after a new study found this ingredient and other stimulants in 17 weight loss and sports supplement products.

The three-year study, published March 23, focused on supplements that contained deterenol, which isn’t approved by the FDA and has never been tested in humans. Researchers at the Netherlands’ National Institute for Public Health and the Environment (RIVM) and Belgium’s Sciensano also participated in the study.

When testing for deterenol in these products, researchers discovered eight additional harmful stimulants, including vonedrine, a drug originally introduced in the 1940s as a prescription nasal spray and later withdrawn from the market by the manufacturer in 1960.

Anyone unknowingly consuming these stimulants could be putting themselves at risk, according to John Travis, who is a senior researcher at NSF and a co-author of the study.

“You never want to find unlabeled ingredients in supplements, but it is especially concerning to find these strange brews of experimental stimulants in products that are readily available in the United States,” Travis said.

Deterenol is a potentially harmful ingredient that has been linked to adverse effects including nausea, vomiting, sweating, agitation, palpations, chest pain and even cardiac arrest.

Deterenol is not approved for use in the United States.

Even more concerning, anyone with existing health conditions – such as high blood pressure or obesity – may be at a higher risk of adverse effects when taking supplements containing deterenol or any of the other eight stimulants found in this study.

“We’re urging clinicians to remain alert to the possibility that patients may be inadvertently exposed to experimental stimulants when consuming weight loss and sports supplements,” said Dr. Pieter Cohen, Associate Professor of Medicine at Harvard Medical School, Internist at Cambridge Health Alliance and a co-author of the study. “These ingredients have no place in dietary supplements.”

Some of these stimulants were disclosed on the label, some were disclosed by a “code word” (such as Acacia rigidula for BMPEA) and some were not disclosed at all. Seven of these stimulants have previously been subject to U.S. FDA regulatory action including product seizures, warning letters and public notices.

During the study, 17 supplement brands were analyzed. Many brands included more than one prohibited stimulant in the same product: four brands (24%) included two stimulants, two (12%) combined three stimulants and two (12%) combined four stimulants. In about half of the brands (47%), deterenol was the only stimulant present.

Dr. Cohen reminds consumers that accurately labeled supplements can play an important role in maintaining a healthy lifestyle.

However, there are a few important safety measures everyone should take before taking any supplements:

• Tell your doctor about any supplements you’re taking
• Avoid any products that list deterenol or one of its synonyms (isopropylnorsynephrine or isopropyloctopamine) as an ingredient
• Look for certified dietary supplements, which are tested to ensure they contain no harmful ingredients

In addition, doctors should continue to ask patients if they’re taking any supplements and help educate them on the importance of looking for certified products.

To better understand the safety of supplements, it’s imperative to know what kind of ingredients are in them, and to not just rely on a product’s labels. Additionally, it’s critical to know how much of certain stimulants are contained in supplements.

“Without understanding these two questions, we can’t even begin to wrap our brains around a product’s potential health risks,” said Dr. Cohen.

The results of the study are clear: Independent testing and certification of supplements is a critical way for consumers to feel confident and safe about the supplements they take.

NSF led the development of the only American National Standard for dietary supplements, which became the foundation of NSF’s accredited dietary supplement certification program in 2001. To earn NSF certification, products are tested for product formulation, label claims and harmful contaminants and ingredients. These products also must be made in a facility that is inspected twice a year.

NSF also created the Certified for Sport® program, in which products must meet additional requirements and are screened for 280 athletic-banned substances. Many professional sport associations, such as MLB, NFL, NHL, PGA, LPGA, CFL and the Canadian Centre for Ethics in Sport, recommend or require the use of Certified for Sport® products.

Consumers with questions about NSF-certified supplements can search our dietary supplements and sports supplements listings, contact the NSF consumer hotline at 1-800-673-8010 or email info@nsf.org.