Lab scientist

CoQ10 products are not equally well absorbed. They do not give equally good health benefits. The bioavailability and the efficacy of the CoQ10 product varies considerably according to the formulation of the product. Consumers of CoQ10 products should seek out documentation for bioavailability and health benefits.

The CoQ10 Association has announced plans to test every Coenzyme Q10 product on the market in the US for potency and purity [Schultz 2020, August 13]. If all goes according to plan, the project will be completed by the end of 2020. We look forward to seeing the results of the testing.

Potency of CoQ10 Products

Testing for potency means ensuring that the capsule contains the quantity of Coenzyme Q10 specified on the label.

Earlier this year, in May, 2020, the NOW nutritional supplements company headquartered in Illinois, revealed that its in-house laboratory had tested 10 CoQ10 products purchased on

The NOW testing showed that only three of the ten CoQ10 products contained 80% or more of the Coenzyme Q10 declared on the product label [Schulz, 2020, May 14].

Purity of CoQ10 Products

Testing for purity means making sure that the CoQ10 products do not contain any adulterating or contaminating substances.

For example, back on February 6 and 7, 2015, the New York Times reported that herbal remedies – ginseng, Ginkgo biloba, St. John’s Wort, and valerian root among them – sold by GNC, Target, Walgreens, and Walmart did not contain the active ingredients listed on the labels.

Buyer, beware!

Documentation of Bioavailability and Health Benefits

Testing for potency and purity is important.

  • Potency and purity are necessary conditions for consumer trust in a product.
  • However, potency and purity are not sufficient conditions.

Consumers of CoQ10 products should purchase products for which the bioavailability of the active ingredient and the associated health benefits have been demonstrated in randomized controlled trials.

Randomized controlled trials are the gold standard for studies of Coenzyme Q10 bioavailability and efficacy.

Bioavailability of Coenzyme Q10

A 2019 double-blind crossover study has shown that there is considerable variation in the bioavailability of individual CoQ10 products depending upon the formulation of the Coenzyme Q10 [Lopez-Lluch 2019].

Efficacy of Coenzyme Q10

Daily supplementation with a well-formulated CoQ10 product has been significantly associated with beneficial health effects in the following studies, all of them randomized controlled trials:

Summing Up: CoQ10 and Quality

Coenzyme Q10 supplements are affordable and safe and well-tolerated.


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Schultz H. NOW Testing Reveals CoQ10, SAMe Products Sold on Amazon to be of Almost Uniformly Low Potency. 2020a, May 14. Retrieved from

Schultz H. CoQ10 Association Plans to Test Every Product on the Market. 2020b, August 13. Retrieved from

The information presented in this review article is not intended as medical advice and should not be used as such.

31 August 2020