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Memory Supplements: Results of Testing for Selected Supplements

GAO-19-23R Published: Oct 18, 2018. Publicly Released: Nov 14, 2018.
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Fast Facts

Do memory supplements contain what they claim? We had three products tested.

One product, marketed as Ginkgo biloba, did not contain that ingredient. Instead it contained an unknown substitute; as such the safety of the product is unknown.

The second product was marketed as a supplement that included Ginkgo biloba. It also contained an unknown substitute, instead of Ginkgo biloba.

The third product, marketed as a fish oil supplement, contained the stated ingredients.

We are sending our results to the Food and Drug Administration for review and possible investigation, in coordination with the Federal Trade Commission.


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What GAO Found

GAO found that two of the three memory supplement products that GAO had tested by a qualified and vetted laboratory either did not contain their stated ingredients or did not contain the ingredient quantity stated on the label. The Ginkgo biloba single-ingredient product that GAO had tested was determined by laboratory scientists to contain no Ginkgo biloba and to be adulterated with one or more unknown substitute ingredients. The second memory supplement product GAO had tested, which consisted of multiple ingredients, contained lower amounts of ingredients than claimed on the label for at least two of the three ingredients tested. In addition, the laboratory found that the Ginkgo biloba in that memory supplement product was adulterated with unknown substitute ingredients. As a result, the safety of the substitute ingredients could not be determined by the laboratory. The fish oil product, the third memory supplement product GAO had tested, contained stated ingredients at quantities above the label amounts. Lastly, the laboratory found trace amounts of contaminants in the selected supplement products, but at levels considered safe.

Why GAO Did This Study

Available data indicate that memory supplements comprise a small segment of the overall dietary supplement market, but their sales nearly doubled in value from 2006 to 2015, increasing to $643 million in 2015. Consumers searching to prevent or treat age-related memory loss, including Alzheimer’s disease, have increasingly turned to dietary supplements for help. Given questions about the effect on senior citizens of the growing memory supplement market, GAO was asked to have selected memory supplements tested. This report examines the extent to which selected memory supplements contained (1) their stated ingredients at the quantities stated on their labels and specific adulterants, and (2) certain contaminants.

GAO contracted with a qualified and vetted testing laboratory to conduct testing on a non-generalizable sample of three memory supplement products selected from a list of highly-advertised products, and based on the popularity of their main ingredient, number of ingredients, and availability of the product from major retailers. The tested products were marketed as a Ginkgo biloba supplement, a specialty memory supplement (which contained multiple ingredients including Ginkgo biloba), and a fish oil supplement. Testing for selected products included: ingredient identity and quantity testing for selected ingredients listed on the label, and testing for certain dangerous contaminants (arsenic, cadmium, chromium, lead, and mercury) in the samples. Laboratory scientists also tested for adulterants in selected supplements containing Ginkgo biloba. The results of this testing are limited to the highly advertised supplement samples that GAO had tested and are not projectable to the entire universe of memory supplements. Technical experts from GAO interviewed scientists from the testing laboratory and reviewed all data and results related to the testing of the memory supplement samples discussed in this report, and determined that the laboratory data were sufficiently reliable for GAO’s purposes.

For more information, contact Seto Bagdoyan at (202) 512-6722 or, or Timothy Persons at (202) 512-6412 or

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