Five out of 11 ginseng supplements recently selected for testing contained less ginseng than expected from their labels or were contaminated with lead and/or pesticides, according to a report from ConsumerLab.com, White Plains, NY.

ConsumerLab.com has reported problems with the quality of ginseng supplements since 2000. Ginseng is a popular herb with U.S. sales last year of $83 million according to Nutrition Business Journal.

“Consumers need to be wary of the quality of ginseng supplements,” said Tod Cooperman, MD, president of ConsumerLab.com. “People should also recognize that there is enormous variation in the amount of ginsenosides—key ginseng compounds—in marketed supplements. We found most products to provide approximately 10 to 40 mg of ginsenosides per day, but some yielded much higher amounts, including one that delivered a whopping 304 mg. We are not aware of human studies with the higher amounts. The effects might certainly differ from one product to another.”

Ginseng has often been promoted for increasing vitality. While there is not much clinical evidence to support an energy boosting effect, studies indicate that certain preparations may help prevent colds and flu or keep blood sugar levels down in people with diabetes. A range of other uses have been suggested but lack strong evidence.

The new Product Review of Ginseng Supplements provides test results for 15 supplements—eleven selected by ConsumerLab.com and four tested at the request of their manufacturers/distributors that passed the same testing through CL’s Voluntary Certification Program. Also listed are two products similar to one that passed testing but sold under different brand names.