Benefits
Heart health outcomes in a 2-year trial
In a 2-year randomized trial of 420 adults with moderate to severe heart failure, 100 mg three times a day added to standard care led to fewer major cardiac events than placebo (15% vs 26% of patients) and fewer cardiovascular and all-cause deaths. Measures taken at 16 weeks did not change. It is one trial in people under medical care, not evidence for healthy hearts.
Less fatigue in pooled trials
A meta-analysis of 13 randomized trials in 1,126 people found lower fatigue scores with CoQ10 than with placebo (Hedges' g -0.40), a small to moderate effect. Results pointed the same way in healthy people and in people with health conditions, and larger daily doses and longer use were linked to bigger reductions. Products and fatigue scales differed between trials.
Antioxidant enzymes and oxidative stress markers
A meta-analysis of 19 randomized trials found that CoQ10 raised total antioxidant capacity and the antioxidant enzymes glutathione peroxidase, superoxide dismutase and catalase, and lowered malondialdehyde, a marker of fat oxidation. Possible publication bias makes the superoxide dismutase and catalase results uncertain, and these are blood markers, not proof of better health outcomes.
Headache frequency
In a 3-month trial of 42 people with migraine, 100 mg three times a day reduced attack frequency, headache days and days with nausea versus placebo; 48% vs 14% halved their attacks. A meta-analysis of 6 trials in 371 adults found fewer and shorter attacks but no change in severity. A US neurology and headache society guideline rates it possibly effective.
Muscle comfort in people taking statins
A meta-analysis of 12 trials in 575 statin users found less muscle pain, weakness, cramps and tiredness, but no change in creatine kinase, a blood marker of muscle damage. A later analysis of 7 trials using 100 to 600 mg a day found a smaller pain reduction (4 trials positive, 3 not), and an NIH review judges the evidence unsupportive. Never stop a statin on your own.
Skin wrinkles and smoothness
In a double-blind trial of 33 healthy volunteers, a water-soluble CoQ10 (Q10Vital) at 50 or 150 mg a day for 12 weeks reduced wrinkles and fine lines, improved smoothness and limited the seasonal loss of skin elasticity. Hydration, dermis thickness and sunburn sensitivity did not change. It is a small trial of one special form, so ordinary capsules may differ.
Ubiquinol and ubiquinone forms
In a crossover study of 21 healthy adults aged 65 to 74, a single 100 mg dose of a water-soluble CoQ10 was absorbed 2.4 times better than standard ubiquinone capsules, while ubiquinol capsules were not significantly better (1.7-fold). Either way, CoQ10 appeared in blood mostly as ubiquinol. Better absorption of one dose does not show better results.
Exercise performance
A meta-analysis of 24 randomized trials in healthy adults found that CoQ10 reliably raised blood levels, but effects on exercise performance were small and inconsistent, with low to very low certainty. Any benefit appeared only with regular use, and strength and sprint outcomes barely changed.
No benefit in a large neurology trial
In a phase 3 trial, 600 people with early Parkinson's disease took placebo, 1,200 mg or 2,400 mg a day (all with vitamin E) for up to 16 months. The trial was stopped for futility: both CoQ10 groups scored slightly worse than placebo on the disease rating scale, though not significantly. The doses were well tolerated.
Mechanism of action
Electron transport and energy
CoQ10 is part of the mitochondrial respiratory chain, carrying electrons in the process that produces ATP, the cell's main energy currency. It is found in all cell membranes and in blood lipoproteins.
Membrane antioxidant
In its reduced form, ubiquinol, CoQ10 protects membrane fats and LDL particles from lipid peroxidation, and it can regenerate vitamin E from its oxidized form. This fat-soluble role differs from water-soluble antioxidants such as vitamin C.
Production and aging
The body makes CoQ10 through the mevalonate pathway, which also makes cholesterol. Tissue levels fall during aging, and drugs that block cholesterol production in this pathway can affect how much CoQ10 the body makes.
What supplements change
Oral CoQ10 mainly raises blood levels, which pooled exercise trials confirm. Absorbed CoQ10 circulates mostly as ubiquinol, even when it is taken as ubiquinone.
Clinical trials
Randomized double-blind multicenter trial: CoQ10 100 mg three times a day or placebo for 2 years, added to standard therapy (Mortensen et al. 2014, JACC Heart Fail)
420 adults with moderate to severe chronic heart failure
The 16-week endpoints (NYHA class, 6-minute walk, NT-proBNP) did not change. At 2 years, major adverse cardiovascular events occurred in 15% on CoQ10 vs 26% on placebo (HR 0.50, 95% CI 0.32 to 0.80, p=0.003); cardiovascular deaths were 9% vs 16% and all-cause deaths 10% vs 18%. This is one trial in medically treated patients.
Systematic review and meta-analysis of 13 randomized placebo-controlled trials (Tsai et al. 2022, Front Pharmacol)
1,126 participants, healthy and with various health conditions
CoQ10 lowered fatigue scores versus placebo (Hedges' g -0.398, 95% CI -0.641 to -0.155, p=0.001). The effect was significant for CoQ10-only products but not for combination products, and larger daily doses and longer use predicted bigger reductions. One gastrointestinal adverse event was reported among 602 people taking CoQ10.
Systematic review and meta-analysis of 19 randomized controlled trials (Sangsefidi et al. 2020, Food Sci Nutr)
Participants in 19 randomized controlled trials
CoQ10 raised total antioxidant capacity (SMD 1.29), glutathione peroxidase (SMD 0.45), superoxide dismutase (SMD 0.63) and catalase (SMD 1.67), and lowered malondialdehyde (SMD -1.12). The authors said the superoxide dismutase and catalase results should be read carefully because of publication bias.
Double-blind randomized placebo-controlled trial, CoQ10 100 mg three times a day for 3 months (Sándor et al. 2005, Neurology)
42 adults with migraine
CoQ10 beat placebo for attack frequency, headache days and days with nausea in the third month. Attacks fell by at least half in 47.6% on CoQ10 vs 14.4% on placebo (number needed to treat 3). It was well tolerated.
Systematic review and meta-analysis of 6 randomized controlled trials (Sazali et al. 2021, BMJ Open)
371 adults with migraine
CoQ10 reduced attack frequency (MD -1.52, 95% CI -2.40 to -0.65) and attack duration (MD -0.19) versus control, but did not significantly reduce headache severity.
Meta-analysis of 12 randomized controlled trials (Qu et al. 2018, J Am Heart Assoc)
575 statin-treated patients (294 CoQ10, 281 placebo)
CoQ10 reduced reported muscle pain (WMD -1.60), weakness (-2.28), cramps (-1.78) and tiredness (-1.75) versus placebo. Plasma creatine kinase did not change (WMD 0.09, 95% CI -0.06 to 0.24, P=0.23).
Systematic review and meta-analysis of 7 randomized controlled trials, 100 to 600 mg a day for 30 to 90 days (Kovacic et al. 2025, J Nutr Sci)
389 adults taking statins
Four trials found a significant reduction in muscle symptoms and three did not. Pooled, pain intensity fell slightly (WMD -0.96, 95% CI -1.88 to -0.03). The authors called for more research before firm recommendations.
Phase 3 randomized double-blind placebo-controlled trial at 67 sites, 1,200 or 2,400 mg a day with vitamin E, up to 16 months (Beal et al. 2014, JAMA Neurol)
600 adults diagnosed with Parkinson's disease within 5 years
The trial was stopped when a futility criterion was reached. Total UPDRS scores worsened by 6.9 points on placebo, 7.5 on 1,200 mg (P=.49) and 8.0 on 2,400 mg (P=.21). No clinical benefit was found; treatment was well tolerated.
Randomized double-blind placebo-controlled trial, water-soluble CoQ10 (Q10Vital) 50 or 150 mg a day for 12 weeks (Žmitek et al. 2017, Biofactors)
33 healthy adults
CoQ10 limited seasonal loss of skin viscoelasticity, reduced wrinkles and microrelief lines and improved smoothness. Minimal erythema dose, skin hydration and dermis thickness did not change significantly.
Randomized three-period crossover bioavailability study, single 100 mg doses with one-week washouts (Pravst et al. 2020, Nutrients)
21 healthy adults aged 65 to 74
Over 48 hours, the water-soluble form was absorbed 2.4-fold better than ubiquinone capsules (p=0.002); ubiquinol capsules were 1.7-fold, not significant (p=0.129). All forms appeared in blood mostly as ubiquinol.
Systematic review and meta-analysis of 24 randomized placebo-controlled studies (Deng et al. 2025, Br J Nutr)
Healthy adults
Supplements consistently raised blood CoQ10. Performance effects were small and inconsistent: regular use showed a small benefit that was not stable after removing outliers, and single doses showed none. Certainty was rated very low to low.