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Study Finds Ubiquinol Reduces Fatigue in Healthy People

How effective is CoQ10 for enhancing energy levels and motivation?

Photo Copyrights owned by Nootralize
Source: Photo Copyrights owned by Nootralize

What is ubiquinol?

Ubiquinol is a form of CoQ10, a nootropic compound that can be synthesized in the human body. Ubiquinol is more bioavailable than most other forms of CoQ10 [4], meaning it will be absorbed better in the body after consumption.

A study on the effects of Ubiquinol-10 on various aspects of cognitive performance and sustained energy levels was published in the journal Nutrients the 2nd of June 2020. Let’s see what the researchers found.

Ubiquinol is a dietary supplement that is legal to buy, possess, and use in Canada and the U.S. [1]

Method — How the study was conducted


The study was randomized and placebo-controlled. An exclusion criterion was the subjective judgment of suitability by the principal investigator, which in itself could bias the selection of participants to those most likely to benefit from the intervention. However, the randomization of participants into the different groups makes it very unlikely this was done for the purpose of altering study results since the participants that might’ve been expected to respond well could’ve ended up in the placebo group or any of the intervention groups.


In a study investigating the contents of total CoQ10 and Ubiquinol in the average Japanese diet, total coenzyme Q10 from food consumption was 4.48 mg and ubiquinol-10 accounted for 46% of the total coenzyme Q10 intake. [2]

In this study, 100mg, and 150mg Ubiquinol were given to two different groups of 20 and 22 participants respectively. The large difference between the usual dietary intake and the dose given to participants in this study means that trying to increase your dietary intake of Ubiquinol is unlikely to lead to any significant effects comparable to those observed in this study.

Measures — Tests

At baseline (week 0), after 4, 8, and 12 weeks, participants completed tests of fatigue, motivation, and relaxation both prior to and after the administration of the 3 tests that measured cognitive functions. The researchers chose this design to get answer the question:

Are people supplementing with Ubiquinol-10 more resistant to fatigue after performing cognitively demanding tasks, than those supplementing placebo?

If the answer would be yes, Ubiquinol could be a useful supplement to prevent decreasing energy levels during sustained mental efforts.

Measures of oxidative stress and autonomic nerve function were also used to study the hypothesized underlying mechanisms of action of Ubiquinol-10. Serum Ubiquinol was also measured to assess the bioavailability of the supplement.


“The 62 analyzed participants were of 20 – 64 years of age, consisting of 10 participants in their 20s, 16 in their 30s, 15 in their 40s, 18 in their 50s, and 3 in their 60s.” [3]

These participants were randomized into three groups. There were 22 participants in the group receiving 150mg Ubiquinol and 20 participants in both the placebo group and the 100mg Ubiquinol group. There were around twice as many females as males in each study group.


The results were presented without baseline data for all measures except for Serum Ubiquinol and the Digit Symbol Substitution Test. This makes adequate statistical analysis harder in our opinion. We at Nootralize sent an email to the study authors asking for the baseline data that was missing from the study and will include an analysis of the information here if we get an answer.

The Digit Symbol Substitution Test

The DSST measures the speed of visual information-processing, and scores may be applicable to several real-world situations such as reading a book or understanding a presentation by a teacher or boss at school or work.

“Participants performed the task of entering as many numbers corresponding to the signals as possible within the 2-min time limit; the number of correct responses was used as the score.” [3]

The scores on this measure increased for the placebo group and the two groups receiving Ubiquinol, suggesting both placebo and learning effects. The participants believed they would perform better due to the action of taking the supplements every day, regardless of what was in the supplements, and they also got more proficient at the test every time they visited the lab.

There was no effect from Ubiquinol-10 in comparison with placebo on this task after 4, 8, or, 12 weeks. This means that after accounting for the placebo and learning effects, there was no effect from Ubiquinol on the DSST at any time point.

Researchers' interpretation of other measures

Figuring out whether Ubiquinol improved the participants' speed of visual information-processing was not the primary goal of the study. Instead, researchers wanted to know what this (and the two other) cognitively demanding tasks did to the energy levels of the participants.

”Ubiquinol intake led to significant improvements in subjective fatigue sensation and sleepiness after the cognitive-fatigue load in both the 100-mg and 150-mg groups compared with that in the placebo group.”

As regards motivation, 150 mg Ubiquinol-10 intake increased the motivated response to cognitive function tasks after 4 weeks, but no significant difference from the placebo group was observed after 8 and 12 weeks. of intake; this suggests that habituation to the task had an impact on the placebo group whose response times gradually shortened

Conclusion — Takeaways

The study authors concluded that Ubiquinol-10:

“… contributes to the improvement of QOL in individuals with mild fatigue by reducing fatigue and sleepiness following cognitive function load, promoting motivated engagement with cognitive function tasks while providing a relaxing effect, and reducing oxidative stress.” ~(QOL = Quality of Life)

New science is constantly being created to investigate the effectiveness of nootropic compounds. There’s a good reason for this. There’s a lack of research on the effectiveness and moderating variables for almost every nootropic that exists. While this study can be a reason to use Ubiquinol-10 as a cognitive enhancer, there are a lot of unanswered questions regarding optimal timing, dosing, and who will benefit the most. To generalize the results, more data from more participants are needed.

This blog post was originally published at It is not a substitute for professional medical advice, diagnosis, or treatment.






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