The Instability of Ubiquinol – Misleading Marketing Claims?

On the Web, I see many incorrect and undocumented marketing claims for ubiquinol supplements. As a long-time Coenzyme Q10 researcher, I worry that consumers will be persuaded by these misleading marketing claims. In this article, I want to give some background information about how the Coenzyme Q10 in supplements is absorbed and transferred in the body.

Choice of Two Different Forms of Coenzyme Q10 in Supplements

Dr. William Judy in the lab
In 2021, I have published the results of the SIBR Research lab studies and large dog studies of the instability of the ubiquinol supplement. The studies show that the ubiquinol in supplements will be converted to ubiquinone in the small intestines prior to absorption, will then be absorbed in the ubiquinone form, and will be converted back to ubiquinol in the lymph.

Let me start by saying that CoQ10 molecules are redox molecules that have an oxidized form called ubiquinone and a reduced form called ubiquinol. Regardless of whether the supplement manufacturer chooses to work with ubiquinone or ubiquinol, he or she must deal with the following problems [Judy 2018]:

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The Instability of Ubiquinol, Part 2 – Dog Studies

The results from large dog studies done by SIBR Research show that orally administered ubiquinol is mostly converted to the ubiquinone form of Coenzyme Q10 by the time it reaches the small intestines [Judy 2021 Part 2].

Dr Judy in the lab
Coenzyme Q10 is an essential bio-nutrient, especially important as we get older. It is a redox molecule with an oxidized state called ubiquinone and a reduced state called ubiquinol. Both are bio-active states. Ubiquinone supplements are more stable and much more tested than ubiquinol supplements. Ubiquinol by nature of being an electron donor is relatively quick to be oxidized to ubiquinone.

In the small intestines, it is then absorbed primarily as ubiquinone. Once it enters the lymph, it is increasingly converted back to ubiquinol.

By the time it leaves the lymph to enter the blood circulation, it is approximately 96 % ubiquinol again.

These findings beg the question: why buy a ubiquinol supplement when the ubiquinol will probably be converted to the ubiquinone form of Coenzyme Q10 prior to absorption?

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The Instability of Ubiquinol Supplements – Lab Studies

At SIBR Research, we have long been concerned about misleading claims for ubiquinol supplements on the Web. It seems that there is a lack of understanding of the processes influencing the absorption and subsequent metabolism of ubiquinol. Moreover, this misunderstanding seems to have been exacerbated by some manufacturers’ incorrect claims regarding the bioavailability of their ubiquinol supplements [Mantle & Dybring 2020].

Dr William V Judy
SIBR Research studies show that the ubiquinol in supplements is very likely to be converted to ubiquinone in the small intestines, to be absorbed as ubiquinone, and then to be converted back to ubiquinol in the lymph.

Basic Information about Ubiquinone and Ubiquinol

  • Ubiquinol is the reduced form of Coenzyme Q10; it is the antioxidant form of Coenzyme Q10.
  • Ubiquinone is the oxidized form of Coenzyme Q10. It is essential for the process of ATP energy generation.

Note: Both forms of Coenzyme Q10 are bio-active forms.

Ubiquinone More Stable than Ubiquinol in Supplements

Ubiquinol molecules are electron donors. Thus, they are inherently unstable. They are constantly looking to give up two electrons. It is this property that first made us wonder whether the ubiquinol in supplements actually gets absorbed as ubiquinol or gets converted to ubiquinone before being absorbed.

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