9 out of 10 Sports Supplements Fail to Accurately List Ingredients on the Label: Study

Nearly 90% of dietary supplements marketed to enhance sports performance fail to accurately list ingredients on their label, according to the findings of a new study, which indicates that many actually contain substances which pose serious health risks for users.

In a report published this month in the medical journal JAMA Network Open, Harvard researchers warn that, in addition to failing to accurately list their ingredients, many sports supplements contain ingredients that are prohibited by the Food and Drug Administration (FDA), including banned stimulants like 1,4-dimethylamylamine or 1,4-DMM.

Researchers studied 57 dietary supplement products and tested them to determine if they contained the ingredients listed on the label. Each supplement chosen for the study contained one of the following ingredients: Rauwolfia vomitoria, methylliberine, turkesterone, halostachine, or octapamine.

The supplements were purchased online, and then analyzed for the presence and quantity of the five ingredients as well as FDA-prohibited ingredients. The products tested were marketed as sports supplements, including stimulant or anabolic effects, which were intended to enhance athletic performance in some way.

Dietary Supplement Labels Often Inaccurate

Of the 57 products analyzed, 89% did not accurately list ingredients on the label, with 40% not even containing any detectable amount of the ingredients that were disclosed.

Among the products that contained ingredients listed on the label, the amount of the ingredients in the product ranged from 0.02% to 334% of the labeled quantity.

Only 11% of products accurately listed their ingredients, coming within 10% of the amounts listed on the label. However, 12%, were found to contain at least one ingredient that was banned by the FDA or other regulatory agencies.

Five different FDA-banned compounds were detected in the supplements, including four synthetic ingredients, 1,4-dimethylamylamine, deterenol, octodrine, oxilofrine, and omberacetam. Six of the tested products contained one of the banned ingredients, and one contained four of the banned ingredients.

Those ingredients are banned for a number of reasons. For example 1,4-DMM can lead to cardiac arrest, stroke, and death. Deterenol can cause mild to severe symptoms, from nausea to cardiac arrest. Octodrine can lead to high blood pressure, energy crashes, rapid heartbeat, and tremors. Oxilofrine can cause vomiting, agitation, and heart problems, while omberacetam can result in depression, anxiety, and sleep problems.

Dietary Supplement Regulations

Prior reports have raised similar concerns about harmful ingredients in dietary supplements, which are not approved or considered safe by the FDA. A 2018 study found nearly 800 over-the-counter supplements contained unapproved active ingredients.

The FDA does not specifically approve individual dietary supplements introduced for sale in the U.S., and does not conduct oversight to test products for safety or effectiveness once they are on the market. However, the FDA does conduct periodic inspections of some supplements, and those inspections typically identify a surprising number of companies that fail to comply with good manufacturing standards related to the purity or composition of the supplements.

The FDA issued a proposal in 2022 to allow manufacturers to submit late safety data for dietary supplements, even if there are new ingredients they previously failed to report as required by law. The proposal would help to increase agency oversight of an industry that is largely unregulated. However, the market for dietary supplements continues to expand at a rapid pace, despite prior research indicating most supplements have little benefit to human health.

The researchers of this latest study recommend doctors warn consumers about the risks some supplements pose. Warnings should highlight that fitness supplements with advertised stimulants or anabolic effects may not be accurately labeled, may contain more of one ingredient or less of another, and may often contain banned ingredients that may have harmful side effects.