The Ginkgo biloba or Maidenhair tree is a beautiful creature, and I’ve several growing myself.

But the gardener’s delight may be a patient’s peril – recent tests suggest some ginkgo products in Australia have been adulterated and that consumers are being conned.

Dr Ken Harvey, Adjunct Senior Research Fellow in the School of Public Health at La Trobe University, has been investigating the issue over the past year, and has some questions for the Therapeutic Goods Administration.

He writes:

“Ginkgo biloba (the Maidenhair tree) is a deciduous tree native to China, Korea and Japan. Ginkgo leaves and seeds have a long history of use in traditional Chinese medicine for a range of conditions. Ginkgo is one of the most widely used herbal medicines in Europe and the United States of America.

There are currently more than 400 products that contain Ginkgo on the Australian Register of Therapeutic Goods (ARTG). These are listed medicines and are commonly indicated for stimulating blood circulation.

On 2 October, 2009 the TGA noted (on their web site) that they had recently conducted tests on twenty-two (22) batches of herbal medicines containing Ginkgo biloba, covering twenty (20) products.

The TGA said:

“In some of the samples tested, elevated levels of quercetin and rutin were noted. These are naturally occurring components found in Ginkgo and many other plants. Variation in the content of these components may occur due to natural variation in the plants or the processing and storage of the herbal material. The TGA is currently working with its expert advisory committees and the complementary medicine industry associations to refine the quality standards for Ginkgo extracts used in medicines available in Australia.”

What the TGA neglected to point out was that one third of the samples tested had, in fact, failed the United States Pharmacopoeia (USP) identity test for Ginkgo biloba (Test B) because they had ratios of flavonoid components that were consistent with adulteration, not natural variation (for more info, see here and here).

It is common knowledge that some Chinese suppliers of cheap Ginkgo use only a little genuine leaf extract and spike it with less expensive sources of flavonoids, such as rutin (from buckwheat). This tricks standard tests that looks only at the total amount of flavonoids, not the spectrum specific to ginkgo. The concept is not dissimilar to
the scandal about melamine being added to milk in China although, fortunately, the compounds used to adulterate ginkgo do not appear to be harmful.

Nevertheless, consumers unknowingly purchasing adulterated ginkgo products are being hoodwinked, sponsors of products who have sourced genuine (but more expensive) extracts of Ginkgo biloba are being disadvantaged and those responsible for supplying adulterated products are clearly engaged in deceptive and misleading conduct as defined in the Trade Practices Act, 1974.

Eleven months ago, on 21/10/2008, I submitted a Freedom of Information (FOI) request to the TGA. I said, “I wish to know if the TGA has ever tested Australian complementary medicines containing Ginkgo biloba for adulteration with added flavonol glycosides or aglycones such as rutin from buckwheat”.

On 04/12/2008 I received a telephone call from Dr David Briggs (then Head of the Office of Complementary Medicines, TGA). He said, “the TGA was looking into this matter”. Subsequently, I heard no more.

On 11/05/2009 I became aware that the TGA had found that a random sample of 20 Australian herbal products containing Ginkgo biloba had failed United States Pharmacopoeia (USP) Identification Test B.

On 13/05/2009 I telephoned the TGA to inquire why I had not been informed about these results. I was told to submit a new FOI request.

On 14/05/2009, I submitted another FOI, “From testing documents held by the TGA, I request the brand and sponsors names of the 20 products tested and the identification of those products that passed and those that failed USP Identification Test B”.

On 01/10/2009, I received a letter from the TGA refusing my FOI request on the grounds that the documents contained information that:

* could adversely effect business (of third parties) if disclosed;

* if disclosed could prejudice the future supply of information from industry.

I have written to relevant government Ministers (Butler and Ludwig) expressing my concern that the TGA had failed to properly balance the public interest for disclosure against commercial interests that support suppression.

This matter is now open for public debate.”


Croakey will send Dr Harvey’s article to the TGA’s media people and ask for a response. We will keep you posted.

Update…and here it is:

From a spokeswoman for the TGA:

“It is important to note first that the TGA has been provided with no evidence of significant safety matters related to Ginkgo products by Dr Harvey.

While presented as a consumer interest matter, this issue appears to have been raised to allow certain companies to attempt to gain a commercial advantage by claiming other products are not meeting standards that are not
actually part of Australian regulatory requirements.

The reasons the TGA is not releasing the information requested under FOI to Dr Harvey include the facts that:
1) no products breached applicable Australian standards at the time of testing,
2) exemptions apply under the FOI Act that exclude the documents from release  as there is the potential for damage to occur to the legitimate interests of third parties, and
3) to release the information to Dr Harvey may be detrimental to the public interest by discouraging future cooperation with TGA testing programs aimed at raising standards of therapeutic products available to the Australian people.

The TGA has released information on its website about Ginkgo and TGA’s ongoing work on this issue.

In order to ensure that the Australian public continues to have access to the highest quality Ginkgo products the TGA is working with its expert scientific advisory committees to clarify appropriate Australian requirements for the composition of Ginkgo products so that there is no ongoing confusion about this matter.”