• abundant in living organisms and required for metabolism and protection from oxidative stress
  • synthesized by the human body and can be absorbed through digestion
  • supplements are available without a prescription
  • fat-soluble and best absorbed with fat in a meal
  • can be supplemented in two forms: Ubiquinol and Ubiquinone
  • levels can be recovered in tissues that have become deficient due to aging or disease
  • can cause gastrointestinal symptoms, such as nausea, diarrhea, appetite suppression, heartburn, and abdominal discomfort, especially with daily doses ≥200 mg
  • has been taken in doses of 3000mg/day for 8 months without causing problems, and lower doses for much longer

Personal experience

I’ve been taking 200mg CoQ10 (Ubiquinone form) daily since April 2022, after recommendation by a neurologist on the assumption that mitochondrial dysfunction was part of my post-viral fatigue syndrome. I had taken it for a couple of months in late 2021 after being inspired by the science behind Terry Wahls’ protocol, but stopped taking all supplements around that time because I became overwhelmed with information about supplementation.

The times I’ve been taking CoQ10 regularly have coincided with periods of slow improvement. In particular I perceived that I could tolerate cognitive tasks for longer after regular CoQ10 supplementation. There is science to support this narrative, but with so many factors to control for it’s impossible to say if it really helped in my case. Given that it is well-researched, ubiquitous, naturally-occurring, and has no discernible side-effects for me, I will probably continue to take CoQ10 even once recovered.


Unless cited as otherwise, the following information is from the Linus Pauling Institute’s Micronutrient Information Center website.

Coenzyme Q10 (CoQ10) is a ubiquitous vitamin-like molecule that is present in all respiring eukaryotic cells, i.e. nearly every cell in your body. It is particularly abundant in the most energy-consuming organs–the heart, kidneys, brain and liver (Wang et al., 2010)–and has the highest concentrations in heart, kidney and liver tissue (Aberg et al., 1992).

Over seventy percent of CoQ10 in human tissues is in the most useful reduced form, Ubiquinol; it can also be found in two states that occur as it protects us from oxidative stress, the more common form being the fully-oxidized form Ubiquinone. Both forms can be purchased as supplements–the more expensive Ubiquinol is allegedly more bioavailable.

CoQ10 and Vitamin E (α-Tocopherol) are the principal fat-soluble antioxidants in membranes and lipoproteins; they work in harmony, and so supplementing both may be beneficial. Additionally, CoQ10 is capable of regenerating ascorbate (vitamin C).


  1. Wang, Z. M., Ying, Z., Bosy-Westphal, A., Zhang, J., Schautz, B., Later, W., Heymsfield, S. B., & Müller, M. J. (2010). Specific metabolic rates of major organs and tissues across adulthood: evaluation by mechanistic model of resting energy expenditure. The American Journal of Clinical Nutrition, 92(6), 1369–1377. https://doi.org/10.3945/ajcn.2010.29885
  2. Aberg, F., Appelkvist, E. L., Dallner, G., & Ernster, L. (1992). Distribution and redox state of ubiquinones in rat and human tissues. Archives of Biochemistry and Biophysics, 295(2), 230–234. https://doi.org/10.1016/0003-9861(92)90511-t