There are numerous enzyme systems at work in the body to convert ubiquinone, the oxidized form of Coenzyme Q10, to ubiquinol, the reduced form of Coenzyme Q10.  Despite marketing claims to the contrary, it is not necessary to take a ubiquinol supplement to get sufficient ubiquinol in the body [Mantle & Dybring 2020].  No worries there.

This is the take-home message in a peer-reviewed journal article published on May 5, 2020, in the Antioxidants journal [Mantle & Dybring 2020].

Ubiquinone (Oxidized Form) and Ubiquinol (Reduced Form)

Coenzyme Q10 molecules are redox molecules. In the body, they convert back and forward between their oxidized form, ubiquinone, and their reduced form, ubiquinol.  What does that mean, oxidized and reduced?

A US supplements manufacturer reports that its testing shows some of the CoQ10 supplements sold on amazon.com do not contain the quantity of Coenzyme Q10 indicated on the product label [Schultz, 2020, May 14].

The testing shows that seven of the ten tested products had less than 80% potency. These seven named products are not products from major sellers of CoQ10 supplements in the USA.

The other three tested products tested are labeled “X Brand” in the test report. These three products are said to contain 93%, 96.5%, and 86% of the declared active ingredient [NOW® Testing].

Fact: Without decent absorption and bio-availability of our CoQ10 supplement, we cannot hope to get good heart health effects.

Fact: There is much variability from one CoQ10 supplement to another. It is important to choose a CoQ10 supplement for which there is documented evidence of absorption and bio-availability as well as published evidence of improvement of heart health signs and symptoms.

Sadly, the claims for the absorption of many CoQ10 supplements have been greatly exaggerated in many cases.

Even if they are made from the same raw material, the CoQ10 products on the US retail market are very diverse in terms of their absorption and in terms of their health effects. 

We, as consumers, need to see documentation, preferably in peer-reviewed scientific journals, for the absorption and efficacy of the CoQ10 product we buy.

The form of the retail Coenzyme Q10 product can be different (either the ubiquinone form or the ubiquinol form), and the formulation can be different (different carrier oils and different heating and cooling processes).

Absorption of the Coenzyme Q10 in commercial nutritional supplements varies considerably.  The dissolution of the CoQ10 crystals and the absorption of the Coenzyme Q10 molecules depend upon the composition of the oil matrix and the formulation of the CoQ10 nutritional supplement.  The manufacturer of a CoQ10 supplement must deal with raw material that is very difficult to work with.

Coenzyme Q10 Soluble in Lipids at Higher Temperatures

Coenzyme Q10 is practically insoluble in water but is soluble in lipids; however, no individual lipids have been found in which 100 milligrams of Coenzyme Q10 can be dissolved so that the dissolved Coenzyme Q10 molecules inside the nutritional supplement capsules will not re-crystallize at normal storage temperatures: typically, between 60 and 75 degrees Fahrenheit.

The CoQ10 molecules in the best nutritional supplements are the same molecules as the CoQ10 molecules synthesized inside the mitochondriaThe mitochondria are the bean-shaped organelles in the cells. They are the key organelles with responsibility for the production of ATP energy molecules.... Read more about this term in human cells.

Absorption and Bio-availability of Coenzyme Q10

Similar to vitamin EVitamin E is a fat-soluble vitamin that plays an important role as an antioxidant in the body. Vitamin E neutralizes harmful free radicals. Coenzyme Q10 regenerates Vitamin E after the vitamin E has neutralized free radicals.... Read more about this term, Coenzyme Q10 in food and in nutritional supplements has a low absorption and bio-availability.  In the case of Coenzyme Q10, the difficult absorption is attributed to the relatively large size and the lipid soluble nature of the CoQ10 molecules.

In the February and March 2019 issues of WholeFoods Magazine, Dr. Richard Passwater has published part 1 and part 2 of his interview with Dr. William Judy. These interviews are must reading [Passwater 2019].

The Main Coenzyme Q10 Points in the Dr. Passwater – Dr. Judy Interviews

Dr. Passwater’s interviews with Dr. Judy focus on current issues in CoQ10 research. These issues are of interest to all of us who want to maintain good heart health.

Coenzyme Q10 Molecules are Redox Molecules With Oxidized and Reduced Forms

Coenzyme Q10 molecules are redox molecules with an oxidized form of Coenzyme Q10 called ubiquinoneUbiquinone, the oxidized form of Coenzyme Q10, expressed as Q10 or CoQ10, is absolutely essential for the mitochondrial ATP energy production process. Ubiquinone is the form of Coenzyme Q10 that the body synthesizes, and ubiquinone is the form of Coenzyme Q10 that has been extensively tested for safety, absorption, and efficacy in clinical trials.... Read more about this term, an intermediate partially reduced form called ubisemiquinonesee redox molecule., and a reduced form called ubiquinol. The ubiquinone and ubiquinol forms are both used in Coenzyme Q10 supplements. Both forms are active and important forms.

Coenzyme Q10 supplements are not all the same.  Some give a much better absorption than others. To get real value for the money we spend on CoQ10 supplements, we need to seek out and buy a product with documented good absorption.

A randomized controlled study done in 2018 has shown that a patented ubiquinone Coenzyme Q10 supplement gives significantly better absorption than a patented ubiquinol supplement [Lopez-Lluch 2018].

Dissolving Coenzyme Q10 crystals to single molecules

The Coenzyme Q10 raw material is a crystalline powder.  These crystals cannot diffuse into the intestinal absorption cells.  The crystals will pass right through the intestinal tract and will be eliminated in the feces.