Several Ginkgo biloba supplements failed to meet quality standards in a recent test of memory- and cognition-enhancing products conducted by ConsumerLab.com, White Plains, NY.

Among the eight Ginkgo biloba products tested, two appeared to contain adulterated material and two others contained less ginkgo than claimed on labels. One of these was contaminated with lead and failed to break apart properly. A fifth product failed to identify the part of the ginkgo plant used, which is an FDA labeling requirement. Only three ginkgo supplements passed ConsumerLab.com’s tests.

The results were reported in the group’s Product Review of Supplements for Memory & Cognition Enhancement, which evaluated huperzine A and acetyl-L-carnitine along with Ginkgo biloba. Among the three huperzine products selected, two passed testing while a third provided only 14% of its claimed amount of the ingredient. All five acetyl-L-carnitine supplements passed testing.

Brands covered in the new report include BioSynergy, Bluebonnet, Cognitive Nutrition, Freeda, Ginkgo-Go!, Ginkoba, Life Enhancements, Nature’s Valley, Nutricology, Olympian Labs, Puritan’s Pride, Solaray, Swanson, Total Nutrition, Universal Naturals, Vitamin Shoppe and Vitamin World.