If You Take Ginkgo Biloba … Watch out for Ginkolic Acid

Ginkgo biloba extract can dramatically improve your mental sharpness, improve your memory, and slow brain aging. But you’d better know how to shop for the best available product … or you may end up wasting your money on a product that has no effect at all or does more harm than good!

We want to alert you, a valued reader of Smart Publications Health & Wellness Update, to some new, vital information that has not been widely disseminated. This information has to do with two crucial issues: the safety and effectiveness of Ginkgo biloba supplements.

1) Safety: Watch Out for Ginkolic Acid!

Most people aren’t aware that Ginkgo leaves contain a toxic compound, ginkgolic acid. Pharmaceutical-grade Ginkgo extract must contain 24% flavonoids, 6% triterpenes, and less than 5 parts per million of ginkgolic acid. But in the US, you can’t be sure how much ginkgolic acid is in your product unless it is specifically stated on the label … and most manufacturers don’t list it on the label. (And the sad fact is that many Ginkgo products contain more – much more ginkgolic acid than is considered safe.)

Know what to look for

Even if the ingredients aren’t on the label, it’s important to learn what makes a Ginkgo biloba extract safe and effective … so you can intelligently ask manufacturers about their product and know what you’re buying!

Standard Ginkgo biloba products contain 24% flavonoids and 6% triterpenes, but the label usually doesn’t tell you anything about the levels of toxic ginkgolic acid.

Although Ginkgo extract must meet the standard described above, plus contain less than 5 ppm of ginkgolic acid in order to be sold as a pharmaceutical in Europe, there has been no such quality control in the US dietary supplement market. This is a major concern for consumers because Ginkgo produced for pharmaceutical use and rejected because it exceeds the 5ppm ginkgolic acid level is often sold as a dietary supplement at inexpensive prices to unknowing consumers.

After all, supplements are not a grocery item! There is a difference in quality and, as we’ve seen, sometimes a difference in safety too. Even with something like vitamin E that might seem like just another commodity item … there is a wide spectrum of grades of vitamin E available to the nutritional supplement manufacturer. A synthetic vitamin E supplement (dl-alpha tocopherol) will be less expensive than a natural vitamin E supplement (d-alpha-tocopherol), but won’t be as bioavailable or effective.

Play it safe

Originally, scientists issued warnings that ginkgolic acid levels have to be controlled because it was found to be an allergen that can cause severe allergic reactions in certain people. We also now know that ginkgolic acid damages DNA (a risk for cancer development) and is toxic to nerve cells and the immune system.1

In one study, mice were injected with ginkgolic acid and had significant immunological reactions that appeared in the lymph nodes. The researchers concluded that every care should be taken to guarantee the most complete removal of these compounds as possible during the extraction process.2

In fact, to the contrary, one independent examination of Ginkgo products showed that some contained THOUSANDS of times the pharmaceutical quality limit of less than 5 ppm ginkgolic acid!3

It is important to not take Ginkgo products that don’t meet the standard of less than 5 ppm Ginkgolic acid (5 parts of Ginkgolic acid per million)!

2) Effectiveness: Make Sure Your Ginkgo has a High Bilobalide Content to Get All the Benefits

New studies have shown that bilobalide, a unique phytochemical that is found only in Ginkgo, may prove to be one of the most significant breakthroughs in brain anti-aging. Bilobalide is a substance that recent research has shown:

  • induces important brain growth factors
  • prevents cell death from amyloid protein—a culprit in Alzheimer’s disease
  • protects mitochondria, the tiny energy factories inside cells that provide the “spark of life”
  • protects against Alzheimer’s and other neurodegenerative disorders
  • prolongs life span
  • works synergistically with the other compounds in Ginkgo

Buying a high-quality Ginkgo supplement that contains at least 3% bilobalide is very important, since the latest research shows bilobalide to be one of the major active components of the extract.4 But most companies don’t tell you the amount that’s in their product.

Imagine what a Ginkgo biloba extract product with 5% bilobalide—more than any other product on the market—can do for you!

Imagine also if that same product had less than 1 part per million of ginkgolic acid, ensuring the lowest possible amount of this undesirable Ginkgo component and being five times LOWER than even the pharmaceutical standard for high-quality Ginkgo.

How safe is Ginkgo?

More than 20 years of research have proven that Ginkgo can revitalize the circulatory system, brain and body in a natural, safe, gentle way. Clinical studies using Ginkgo with less than 5ppm Ginkgolic acid have shown Ginkgo to be remarkably free of side effects. The same is not known for Ginkgo exceeding this standard. Unfortunately, Ginkgo products on the shelf today can contain THOUSANDS of times the allowed limit of toxic Ginkgolic acid. It is extremely important to only use Ginkgo meeting the pharmaceutical standard of less than 5 ppm Ginkgolic acid. Ginkgo meeting this standard has been shown to be safe and effective throughout decades of international research.

Individuals who are on blood-thinning medications, however, are cautioned to consult with their health care practitioners before taking Ginkgo.


  1. Westendorf J, Regan J. Induction of DNA strand-breaks in primary rat hepatocytes by ginkgolic acids. Pharmazie. 2000 Nov;55(11):864-5.
    Ahlemeyer B, Selke D, Schaper C, Klumpp S, Krieglstein J. Ginkgolic acids induce neuronal death and activate protein phosphatase type-2C. Eur J Pharmacol. 2001 Oct 26;430(1):1-7.

  2.  Koch E, Jaggy H, Chatterjee SS. Evidence for immunotoxic effects of crude Ginkgo biloba L. leaf extracts using the popliteal lymph node assay in the mouse. Int J Immunopharmacol. 2000 Mar;22(3):229-36. 
    Baron-Ruppert G, Luepke NP. Evidence for toxic effects of alkylphenols from Ginkgo biloba in the hen’s egg test (HET).Phytomedicine. 2001 Mar;8(2):133-8.

  3. Kressmann S, Muller WE, Blume HH. Pharmaceutical quality of different Ginkgo biloba brands. J Pharm Pharmacol 2002 May;54(5):661-9
  4. Defeudis FV. Bilobalide and neuroprotection. Pharmacol Res 2002 Dec;46(6):565-8.
    Janssens D, Remacle J, Drieu K, Michiels C. Protection of mitochondrial respiration activity by bilobalide. Biochem Pharmacol. 1999 Jul 1;58(1):109-19.

    Zheng SX, Zhou LJ, Chen ZL, Yin ML, Zhu XZ. Bilobalide promotes expression of glial cell line-derived neurotrophic factor and vascular endothelial growth factor in rat astrocytes. Acta Pharmacol Sin. 2000 Feb;21(2):151-5. 

    Tendi EA, Bosetti F, Dasgupta SF, Stella AM, Drieu K, Rapoport SI. Ginkgo biloba extracts EGb 761 and bilobalide increase NADH dehydrogenase mRNA level and mitochondrial respiratory control ratio in PC12 cells. Neurochem Res. 2002 Apr;27(4):319-23.