New Study Reveals Supplement Labels for Caffeine are Inaccurate

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Collaborative study between NSF International, Harvard Medical School and the Uniformed Services University finds that supplements widely available at military bases are mislabeled for caffeine.

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Without accurately knowing the caffeine content in a supplement, people run the risk of consuming unhealthy levels of caffeine.

Caffeine levels in dietary supplements commonly used by military personnel are often incorrectly labeled, according to a recent study conducted by NSF International, Harvard Medical School and the Uniformed Services University. The study, which was published in the Journal of the American Medical Association Internal Medicine last week, looked at 31 of the most popular dietary supplements sold as capsules on military installations. Samples from the supplements were analyzed for caffeine content per serving and compared against what was listed on the product label. NSF International, an independent public health organization specializing in the testing of nutritional supplements among other products, conducted the analysis.

The study found that the caffeine content in supplements is inconsistent and often times inaccurate:

Of the 20 dietary supplement products that listed caffeine on the label, 6 products (30 percent) failed to state the amount of caffeine on the label. These products contained high amounts of caffeine, ranging from 210 to 310 mg per serving. To put this in perspective, an eight-ounce cup of coffee has approximately 100 mg of caffeine.

5 of the 20 products (25 percent) were inaccurately labeled containing a dose of caffeine that was at least 10 percent more or less than the labeled amount.

Only 9 of the products (45 percent) listed an accurate amount of caffeine on the label.

"This study highlights the inconsistent labeling practices of many dietary supplement manufacturers. Many of the supplements tested failed to provide clinically accurate and useful information about caffeine content," said Ed Wyszumiala, General Manager of the Dietary Supplement Certification Programs at NSF International. "It is common for military personnel and general consumers to drink other caffeinated beverages, like coffee, soda and energy drinks, throughout the day. Without accurately knowing the caffeine content in a supplement, people run the risk of consuming unhealthy levels of caffeine."

"Studies like this highlight the need for more testing of supplements," said Wyszumiala. "This is why NSF International developed an American National Standard for testing dietary supplements so consumers can look for products that are tested and certified to ensure what’s on the label matches what’s in the bottle and there are no unacceptable levels of contaminants."

Caffeine intake in the form of energy drinks is common practice in the military. A recent study from the Centers for Disease Control and Prevention found that 45 percent of service members consume energy drinks on a daily basis. Yet, federal law does not require that these drinks list caffeine content on the label.

The NSF International/Harvard/USU study also looked at herbal ingredients in dietary supplements that are known to naturally contain caffeine to understand if the caffeine content was properly disclosed on the supplement label. Findings revealed that 11 supplements listed an herbal ingredient that naturally includes caffeine but did not list “caffeine” on the label.

For more information on caffeine in dietary supplements and for tips on how to choose safer supplements, please visit

CONTACT: Greta Houlahan ­- NSF International - Phone: 734-913-5723 - Email: houlahan(at)nsf(dot)org

Supplement Study Methodology:The study, funded by the Department of Defense, identified the most popular dietary supplements sold as capsules (excluding drinks and gels) on military installations labeled as containing either (1) caffeine or (2) one or more herbal ingredient known to naturally contain caffeine but without “caffeine” listed on the label. Supplements were purchased at a large, local retail store selling dietary supplements. The quantity of caffeine per serving in the supplements was determined by high-pressure liquid chromatography with UV (HPLC-UV) absorbance after solvent extraction. If the caffeine level was below the limit of quantitation by the HPLC-UV method, liquid chromatography with tandem mass spectrometry detection was used. The results obtained were compared with the caffeine content listed on the product label. All analyses were performed by NSF International.

About NSF International: NSF International is a global, independent public health organization that writes standards, and tests and certifies products for the food, water, health sciences and consumer goods industries ( Founded in 1944, NSF is committed to protecting human health and safety worldwide and operates in more than 150 countries.

NSF Health Sciences Division offers training and education, consulting, auditing, GMP and GLP testing, certification, R&D and regulatory guidance for the pharmaceutical, medical device and dietary supplement industries throughout the product lifecycle. The division also supplies pharmaceutical secondary reference standards, traceable to USP and EP standards. NSF wrote the only accredited American National Standard (NSF/ANSI 173) that verifies the health and safety of dietary supplements and also tests and certifies products to this standard. The NSF Health Sciences Division operates globally throughout North America, Europe, the Middle East, Africa, Asia and Latin America.

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