Low quality ingredient appears widespread among Ginkgo supplements according to consumerlab.com; points to challenge for FDA's proposed regulations

Townsend Letter for Doctors and Patients, July, 2003

In contrast to its findings three years ago, ConsumerLab.com announced in April that only 22% of the Ginkgo biloba supplements it recently tested met its quality standards. In late 1999, 75% of the products it tested met these standards. Ginkgo, which is used to improve cognitive functioning, remains a top-selling herb in the US, although sales fell by 29% to $47 million in the past year according to market research firms SPINS and ACNielsen.

Ginkgo supplements are generally made from a highly concentrated leaf extract. Products that have been effective in clinical trials contain defined amounts of special compounds from the leaf. Many products on the market claim to be standardized only to total amounts of these compounds and not to the individual compounds. ConsumerLab.com's testing found most ginkgo products to contain less than one-fifth of the expected amount of bilobalide -- a compound that may play a particularly important role in the effectiveness of ginkgo due to its ability to increase brain activity.

"While consumers are often told to look for 'standardized' ginkgo, the standards used by many manufacturers do not measure up to those used in clinical studies," said Tod Cooperman, MD, President of ConsumerLab.com. "It's like selling a car with only one cylinder: It's still a car, but it is not likely to perform well. This may also help explain why sales of ginkgo have been falling." ConsumerLab.com's findings also pose a challenge to the FDA's proposed rules for the labeling of supplements since they do not clearly define standards for herbal ingredients.

A more recently introduced supplement for improving cognitive functioning (particularly in Alzheimer's patients) called huperzine A was also tested in the recent Review. All of the huperzine products contained the labeled amount of the ingredient, but one was found to be high in lead.

Test results for all products reviewed (9 Ginkgo biloba and 4 huperzine A supplements) are now available at www.consumerlab.com/ginkgo.asp. Also listed are results for one additional ginkgo product that passed the same analysis in CL's Voluntary Certification Program. CL's Reviews of 40 other popular types of supplements are also available online. Reviews soon to be released include Calcium, Saw Palmetto, Cholesterol-Lowerers (Sterols, Policosanol and Guggulsterones), and Muscle Enhancers (Creatine, HMB, and Glutamine). ConsumerLab.com's Guide to Buying Vitamins and Supplements is scheduled for print publication this year.

ConsumerLab.com is a leading provider of consumer information and independent evaluations of products that affect health and nutrition. The company is privately held and based in White Plains, New York. It has no ownership from, or interest in, companies that manufacture, distribute, or sell consumer products. ConsumerLab.com is an affiliate of PharmacyChecker.com, an evaluator of online pharmacies. Subscription to Consumerlab.com is available online. Those interested in group subscriptions, Technical Reports, or having additional products tested should contact Lisa Sabin, Vice President for Business Development, at lisa.sabin@consumerlab.com.