What it is
Coenzyme Q10 takes part in electron transport in the mitochondria and acts as a fat-soluble antioxidant. The body makes it on its own and the diet provides 3 to 6 mg per day according to the Linus Pauling Institute; tissue concentrations fall with age without it being known whether that constitutes a deficiency. People buy it mostly for energy, the heart and muscle pain on a statin.
What the label does not say
- Less than 5% of the oral dose would reach the circulation according to the Linus Pauling Institute. Bioavailability depends first on the carrier (oil, dispersion of the crystals): two products showing 100 mg do not deliver the same thing, and the ubiquinol versus ubiquinone argument plays out less on the form than on the formulation.
- Statins: the mechanism is real (they block an enzyme shared by cholesterol and CoQ10 synthesis and lower blood CoQ10), but the trials diverge. A 2015 meta-analysis (six small trials, 100 to 400 mg per day) found no reduction in muscle pain; another from 2018 (12 trials, 575 patients) reports improvement in pain, weakness and cramps. The NCCIH concludes that the data as a whole do not support the idea that CoQ10 reduces statin-related muscle pain.
- Heart failure: the Q-SYMBIO trial (420 patients, 100 mg three times a day for 2 years) reports 15% major cardiovascular events versus 26% on placebo, with no effect on symptoms at 16 weeks. The 2021 Cochrane review (11 trials, 1,573 participants) judges the data of low to very low quality and finds no convincing evidence for or against. This is a use framed by cardiology follow-up, not an energy supplement.
- The doses in the cardiac trials range from 30 to 300 mg per day and the Health Canada monograph sticks to that: 30 to 300 mg for cardiovascular health, 150 to 300 mg for at least 3 months for migraine prevention.
The forms on the shelf
- Ubiquinone: the oxidized form, the most studied, and the only one covered by the Health Canada monograph.
- Ubiquinol: the reduced form, sold as better absorbed. A crossover trial in 10 older men reports a rise in plasma CoQ10 from 1.3 to 3.4 micromoles/L with 200 mg of ubiquinol, with no significant change with ubiquinone. But in a comparison of seven formulations, a ubiquinone with crystals dispersed in an oil gave about twice the exposure of ubiquinol, which reoxidizes into ubiquinone in the stomach in about 90 minutes according to a 2020 review.
- Dry powder in a capsule versus an oil-based softgel: the same review reports that a non-dispersed crystalline ubiquinone loses about 75% of its bioavailability.
Published reference values
- No recommended intake or upper limit: it is not an essential nutrient.
- The Linus Pauling Institute puts the observed safe level at 1,200 mg per day; digestive effects (nausea, diarrhea, heartburn, loss of appetite) reported mostly at 200 mg and above per day, hence split doses above 100 mg.
- On hypertension, the NCCIH judges that the little data available probably suggest no significant effect; the other indications rest on too little data to conclude.
When
Fat-soluble: with a meal containing fat, in an oil-based softgel rather than a dry powder. Above 100 mg, in two or three doses.
Keep apart from
- Warfarin: a few cases of reduced anticoagulant effect reported by the Linus Pauling Institute; Health Canada asks for medical advice above 100 mg per day in people on an anticoagulant. INR monitoring, not spacing doses by the hour.
- Insulin and blood pressure medications: possible interaction with insulin according to the NCCIH; advice required by Health Canada for anyone on blood pressure medication.
To mention to a professional
- Anticoagulants, heart failure, blood pressure medication, ongoing chemotherapy (possible incompatibility according to the NCCIH), pregnancy and breastfeeding (the Linus Pauling Institute advises against it during breastfeeding for lack of data): check with a health care professional.
What it is sold for, and what the data show
CoQ10 is sold for energy, anti-aging and muscle pain on a statin. No trial found shows an energy gain in a healthy person; on statins, two meta-analyses contradict each other and the NCCIH leans toward no effect; on heart failure, the Q-SYMBIO signal remains to be confirmed according to Cochrane.
From the plate first
According to the Linus Pauling Institute: beef 2.6 mg per 3 ounces, pickled herring 2.3 mg, chicken 1.4 mg, soybean oil 1.3 mg per tablespoon, trout 0.9 mg, peanuts 0.8 mg per ounce. The diet provides 3 to 6 mg per day, very far from the doses in capsules.
Sources
- NCCIH, Coenzyme Q10
- Linus Pauling Institute, Micronutrient Information Center, Coenzyme Q10
- Mortensen et al., The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO, JACC Heart Failure, 2014
- Cochrane, Coenzyme Q10 for heart failure (Al Saadi et al., 2021), plain language summary
- Qu et al., Effects of Coenzyme Q10 on Statin-Induced Myopathy: An Updated Meta-Analysis of Randomized Controlled Trials, Journal of the American Heart Association, 2018 (DOAJ record)
- Health Canada, natural health product monograph, Coenzyme Q10 (ubiquinone-10)
- Mantle and Dybring, Bioavailability of Coenzyme Q10: An Overview of the Absorption Process and Subsequent Metabolism, Antioxidants, 2020
- Zhang et al., Ubiquinol is superior to ubiquinone to enhance Coenzyme Q10 status in older men, Food & Function, 2018
Educational information, drawn from the sources above. It does not replace the advice of a health professional, who remains the reference for your situation, your medications, pregnancy or breastfeeding.