Ginkgo: Current Quality and Identity Issues Revealed


Ginkgo biloba is one of the top ten most popular herbs used today by consumers. As we have seen when an herb is a big seller, particular care must be taken to confirm identity and potency in the face of a higher risk of economic adulteration. Dietary supplement manufacturers are legally required to follow the cGMP’s as per the FDA’s 21 CFR, Part 111, as a way to ensure the quality and identity of supplements. However, we see so much adulteration that it’s clear not enough scrutiny is being brought to sourcing this herb.

Ginkgo biloba, also known as Maidenhair, has been traced back nearly 300 million years, making it the oldest surviving tree species on earth. The Chinese have used the plant medicinally for eons but many of the modern applications come from the research of scientists in Germany, where Ginkgo is a prescription herb.

There are many claims made for the therapeutic benefits of Ginkgo, some of which have been demonstrated scientifically and others that remain anecdotal. Ginkgo extract is purported to have benefits for elderly people. This ancient herb acts to enhance oxygen utilization and is said to improve memory, concentration, and other mental faculties. The herbal extract has also apparently shown to significantly improve long-distance vision and may reverse damage to the retina of the eye. Studies have also demonstrated its value in the treatment of depression in elderly people. The Ginkgo extract may provide relief for those who suffer from headaches, sinusitis, and vertigo. It may also help relieve chronic ringing in the ears known as tinnitus.

Alkemist Labs has been testing this material for quality and identity for almost 20 years, and we have seen Ginkgo adulteration frequently throughout the years. This adulteration has taken many forms over time, as regulators, dietary supplement manufacturers, research scientists and testing laboratories have all discovered the many devious ways unscrupulous ingredient suppliers, predominantly in China, have devised to modify, fortify and/or adulterate Ginkgo biloba extract (GBE).

Based on the samples we have analyzed, we have seen that adulteration began with the fortification of GBE with specific flavonoid compounds like Rutin, that would increase the quantitative aspects of its’ quality to meet the 24% minimum quantity of flavonoids needed for various Pharmacopoeia. Based on this requirement, many ingredient suppliers began to look for alternate ways to increase the flavonoid content by either adding those compounds directly to their GBE’s or by adding in certain botanicals, like Sophora japonica and other similar isoflavone/flavonoid containing herbs to again increase or fortify the flavonoid content of the GBE.

We later detected evidence showing that hydrolysis of both Ginko biloba as well as Sophora japonica was occurring in the production of GBE. Hydrolysis is a chemical process in which a molecule of water is added to a substance by using an acid or base to achieve bond cleavage. Through hydrolysis, bound flavonoids can be liberated to increase the overall flavonoid levels thus meeting pharmacopoeial quality standards without having to increase the amount of Ginkgo biloba leaves used in production.

Our investigations have evolved with the changing supply of Ginkgo we were receiving for analysis. The quantitative aspects of GBE quality have always stayed the same; especially since the flavonoid content was being fortified to meet those specs. On the other hand, the identity aspect of GBE has been nothing less than interesting and definitely challenging due to the constant changing manufacturing practices of the ingredient suppliers to be able to (falsely) meet the pharmacopoeial specs.

High Performance Thin-Layer Chromatography (HPTLC) is a simple, effective and cost efficient method of analysis for measuring identity and quality of botanicals, as it has been for over a century. While for many years, the degree of adulteration and/or modification of GBE’s was under-reported, with increased scrutiny and scientific investigation, research papers were published that brought the truth out. We began to look at this adulteration more closely and were astonished to find that there was little GBE in the market place that was what it was claimed to be. Our findings, from analyzing over 1,000 samples, indicate that most of the GBE being sold in the marketplace contains either hydrolyzed Ginkgo biloba, a combination of hydrolyzed G. biloba and hydrolyzed Sophora japonica or other similar herbs, or any combination of these.

In order for us to be certain that our findings were, in fact, accurate, we devised a method of analysis using two different HPTLC methods to help confirm our findings. One of the methods we use is the recommended Pharmacopoeial method, which is inadequate to see the adulteration by itself unless one knows what to look for, and the other is an alternate HPTLC method that clearly demonstrates the difference between adulterated and non-adulterated GBE.

Now that we routinely run both methods for any GBE samples we receive for identity testing we find that most (if not all) GBE that is made in China is adulterated in one way or another. GBE from other continents does not seem to have this problem but there is a price to pay to get the quality of GBE required by the cGMP’s.

We are hopeful that with increased awareness of this significant, ever present problem with GBE, more and more dietary supplement manufacturers will insist on only purchasing the right quality and correct identity of GBE, even though the cost of this GBE is much higher than substandard GBE.

From my personal and professional perspective, and I think everyone who has the knowledge that herbs actually do have beneficial therapeutic effects will agree, there is no other choice but to make sure that consumers get what they are paying for and know with confidence and certainty that “what is on the label, is actually in the bottle”.

Sidney Sudberg

Sydney Sudberg

Each month Sidney Sudberg, Alkemist Founder & CSO, helps to demystify the science behind testing by discussing a testing-related topic.


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