Coenzyme Q10

Q: What is coenzyme Q10?

Coenzyme Q10 (CoQ10) is a substance your body makes and uses in cells to produce energy. It also acts as an antioxidant. Ubiquinone and ubiquinol are its two chemical forms.

Q: Do I get CoQ10 from food?

Yes, a few milligrams a day. Meat, fish, nuts and some oils have the most. Typical diets give about 3 to 6 mg a day, mostly from meat and poultry.

Q: Is CoQ10 good for the heart?

In heart failure, reviews found probably fewer deaths and hospital stays when CoQ10 was added to usual care, but the evidence is mostly from one large trial and Cochrane calls it not convincing. For preventing heart disease, NCCIH says results are inconclusive. It does not replace heart medicines.

Q: Does CoQ10 help with statin muscle pain?

Studies disagree. One meta-analysis found less pain, two found no clear benefit, and NCCIH says the overall evidence does not support it. Do not stop a statin without asking your prescriber.

Q: Does CoQ10 lower blood pressure?

A Cochrane review found it probably has no clinically meaningful effect, though the trials were very small.

Q: Does CoQ10 help with migraine?

Six small trials found fewer and shorter attacks but no change in severity. Some combined CoQ10 with other supplements, so the evidence is low in certainty.

Q: Does CoQ10 help Parkinson disease?

A large trial in early Parkinson disease found no benefit. NCCIH says CoQ10 is not helpful for Parkinson symptoms.

Q: Is ubiquinol better than ubiquinone?

Studies disagree. A 12-person study found higher blood levels after ubiquinol, but a 21-person crossover found no significant difference. Blood levels are not the same as benefit.

Q: Is CoQ10 safe?

NCCIH says no serious side effects have been reported and mild ones such as insomnia or stomach upset can occur. NCI also lists raised liver enzymes, headache, dizziness and rash. Published safety reviews found low toxicity.

Q: Does CoQ10 interact with medicines?

NCCIH and NCI say it may change how the body uses warfarin and insulin, and it may not be compatible with some cancer treatments. One small trial found no change in warfarin dose. Ask a pharmacist before combining.

Ubiquinone / ubiquinol (CoQ10) · also called CoQ10, coenzima Q10, ubiquinona, ubiquinol, ubidecarenone

Coenzyme Q10 is a substance your body makes and cells use for energy. It is also sold as a supplement. The best human evidence is in heart failure, where it was linked to fewer deaths and hospital stays, though reviewers call it not convincing; it did not help early Parkinson disease or blood pressure. Ask a doctor or pharmacist first if you take warfarin, insulin or cancer treatment.

General information, not medical advice. Last substantive update October 26, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

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About Coenzyme Q10

Coenzyme Q10 is made by your body and found in most tissues. Food gives only a few milligrams a day. Supplements have been tested mainly in heart failure, with weaker or negative results for several other uses.

What coenzyme Q10 is

Coenzyme Q10, or CoQ10, is a fat-soluble substance your body makes. NCI says it is found in most tissues, with the most in the heart, liver, kidneys and pancreas, and that levels fall with age. In cells it helps turn food energy into cell energy and acts as an antioxidant in membranes.

It comes in two chemical forms: ubiquinone (the standard supplement form) and ubiquinol (the reduced form). Blood tests found CoQ10 mostly as ubiquinol even after ubiquinone was swallowed.

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When the body is short of it

A very rare inherited condition, primary CoQ10 deficiency (fewer than 1 in 100,000 people), stops the body making enough CoQ10. MedlinePlus Genetics says nerve, muscle and kidney problems get worse unless treated with CoQ10 supplements, under specialist care. For healthy people, no source read shows that extra CoQ10 adds energy.

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Food sources

A 2010 review says meat, fish, nuts and some oils are the richest food sources, with much less in dairy, vegetables, fruit and cereals. Average intake is about 3 to 6 mg a day. A Danish survey found most came from meat and poultry, and that frying destroyed 14% to 32% of CoQ10 while boiling destroyed no detectable amount.

USDA FoodData Central does not list CoQ10, so per-portion amounts are not given.

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What the research shows

The best evidence is for heart failure as an add-on to usual treatment: two reviews found probably fewer deaths and hospital stays, though the Cochrane authors say there is no convincing evidence either way. Results for statin muscle pain disagree. Small trials suggest fewer migraine attacks and better semen measures and blood-sugar markers, all low in certainty. A Cochrane review found no meaningful effect on blood pressure, and a large trial found no benefit in early Parkinson disease.

No trial was read showing that CoQ10 helps healthy people who are not short of it.

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Ubiquinone versus ubiquinol

In 12 healthy volunteers, blood CoQ10 rose more after ubiquinol than ubiquinone. In 21 older adults, a water-soluble syrup was absorbed 2.4 times better than a ubiquinone capsule, but ubiquinol was not significantly better. Blood levels are not the same as benefit, and one product tested was a branded formulation.

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Food versus pills

Almost all trial results above are for supplements. Food gives a few milligrams a day along with other nutrients. No trial compared food CoQ10 with pills. This page gives no amounts to take; if you wonder about your own needs, ask a doctor, pharmacist or dietitian.

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At a glance

Traditional uses history, not proof

Made by the body and found in small amounts in meat, fish and nuts
Sold as a supplement for heart health, energy and statin muscle aches

Studied for research

Role in the body, high certainty
Heart failure add-on, moderate certainty
Heart surgery complications, low certainty
Statin muscle symptoms, mixed
Migraine, male fertility, diabetes markers, low certainty
Blood pressure and Parkinson disease, evidence against

Main compounds

Ubiquinone (oxidised form)
Ubiquinol (reduced form)

Common forms

Food sources (meat, fish, nuts, some oils)
Capsules and soft-gels
Water-soluble syrups

Research links: 2021 Cochrane review: CoQ10 for heart failure (11 trials) · 2014 Q-SYMBIO trial in heart failure · 2014 QE3 trial in early Parkinson disease · 2016 Cochrane review: CoQ10 and blood pressure · NCCIH: Coenzyme Q10 · Research Library · Genes & Biomarkers Library

What it is and its history

Accepted scientific name: Coenzyme Q10 (CoQ10, ubiquinone)
Synonyms: ubiquinone; ubiquinol (reduced form); ubidecarenone; CoQ10
Common names: Coenzyme Q10 (English); CoQ10 (English); Coenzima Q10 (Spanish); Ubiquinona (Spanish); Ubiquinol (Spanish)
Family or group: A fat-soluble substance that is made in the body and found in cell energy structures (mitochondria). It is not an essential vitamin; the body makes it.
Look-alikes and adulterants: Name: Ubiquinol; Note: The reduced form of CoQ10. Studies show CoQ10 appears in the blood mostly as ubiquinol even when ubiquinone is swallowed (Pravst 2020).; Name: Coenzyme Q9; Note: A related form mentioned in a 1997 Danish food survey; not covered here.
Sustainability and conservation: Not assessed.

What is inside, and how it may work

What it contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.

Main compounds

Compound	Family	Where it is concentrated	Activity studied	Level of evidence
Ubiquinone	oxidised form of CoQ10	Not read from a source.	The standard supplement form, studied in the heart failure and Parkinson trials. In a 2020 single-dose study, ubiquinone capsules were absorbed less than a water-soluble syrup. ^{11 12 14}	Human data
Ubiquinol	reduced form of CoQ10	Not read from a source.	In a 12-person study blood CoQ10 rose more after ubiquinol than after ubiquinone; a larger crossover in 21 older adults found no significant difference. ^{10 14}	Human data

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
Cell energy production (oxidative phosphorylation)	Not applicable	CoQ10 plays an essential role in the mitochondrial process that turns food energy into cell energy. ²²	Human data
Antioxidant in cell membranes	Not applicable	In membranes CoQ10 protects cells from free radicals. This is a laboratory-level role and does not show that a supplement prevents disease. ^{22 24}	Lab
Making CoQ10 (COQ genes)	COQ2, COQ4, COQ6, COQ8A, COQ8B and others	Changes in these genes cause primary CoQ10 deficiency. ²²	Human data
Effect of statins on blood CoQ10	Not applicable	Statin treatment lowered circulating CoQ10 in a pooled analysis of 12 trials. ¹⁶	Human data

Absorption, metabolism and elimination

Absorption: Absorption was measured as blood levels after a dose. A water-soluble syrup gave 2.4 times the absorption of ubiquinone capsules in 21 older adults; ubiquinol capsules were not significantly better (1.7-fold, wide interval). A smaller 12-person study found higher blood levels after ubiquinol than ubiquinone over 4 weeks.
Distribution: Highest tissue levels are in the heart, liver, kidneys and pancreas (NCI).
Metabolism: CoQ10 appeared in the blood mostly as ubiquinol even when swallowed as ubiquinone (Pravst 2020).
Elimination: Not read.
Bioavailability: Varies with the product; blood levels are not the same as clinical benefit. The two studies read disagree on ubiquinol versus ubiquinone.

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Isolated compounds versus whole extracts

Food supplies a few milligrams of CoQ10 a day, mostly from meat and poultry, together with fats and other nutrients. Almost all trial results above are for supplements. No trial compared food CoQ10 with pills.

Nutritional composition

Foods richest in CoQ10 by a 2010 review: meat, fish, nuts and some oils. A Danish survey (1997) found 64% of intake from meat and poultry and that frying destroyed 14% to 32% of CoQ10. USDA FoodData Central does not report CoQ10, so no per-portion amounts are given.

12benefits and uses looked at

25studies and sources checked

High certaintybest evidence rating found

13lab markers tracked in trials

1 high certainty2 moderate certainty1 mixed findings4 low certainty2 not enough evidence2 evidence against

What was looked at

The 12 benefits and uses checked for Coenzyme Q10, each with how strong the evidence is. Tap one to open it.

What CoQ10 does in the bodyHigh certainty
Rare inherited CoQ10 deficiencyNot enough evidence
Food sources of CoQ10Moderate certainty
Heart failure (add-on to usual care)Moderate certainty
Complications after heart surgeryLow certainty
Muscle symptoms from statin medicinesMixed findings
Blood pressureEvidence against
Migraine preventionLow certainty
Parkinson diseaseEvidence against
Male infertility (semen quality)Low certainty
Type 2 diabetes blood-sugar markersLow certainty
Cancer treatment supportNot enough evidence

Lab markers tracked in the studies

Death from any cause (heart failure)Hospital stays for heart failureHeart pumping strength (ejection fraction)Muscle pain score on a statinBlood creatine kinase (CK)CoQ10 level in the blood during statin treatmentSystolic blood pressureMigraine attacks per monthParkinson symptom score (UPDRS)Sperm motilitySperm concentrationClinical pregnancyHbA1c

What is Coenzyme Q10 good for?

The main studied uses and how strong the human evidence is for each. Most results are for supplements in people with a medical condition, not healthy people.

What CoQ10 does in the bodyHigh certaintyThe body makes CoQ10 and cells use it to make energy. It also works as an antioxidant in cell membranes. The most is found in the heart, liver, kidneys and pancreas, and levels fall with age. This describes normal body function; it does not show that extra pills add benefit. Rare inherited CoQ10 deficiencyNot enough evidenceIn a very rare inherited condition (fewer than 1 in 100,000 people) the body cannot make enough CoQ10. MedlinePlus Genetics says nerve problems get worse unless treated with CoQ10 supplements, under specialist care. No treatment trial was read, so the strength of the evidence is not rated. Food sources of CoQ10Moderate certaintyMeat, fish, nuts and some oils are the richest sources; dairy, vegetables, fruit and cereals have much less. Typical diets give about 3 to 6 mg a day, mostly from meat and poultry. Frying lowered CoQ10 by 14% to 32% in one survey. Heart failure (add-on to usual care)Moderate certaintyA 2021 Cochrane review found CoQ10 probably meant fewer deaths and fewer hospital stays, mostly from one large trial. A 2024 review of 33 trials agreed. Effects on heart pumping and exercise were very uncertain, and the Cochrane authors say the evidence is not convincing. It never replaces heart medicines. Complications after heart surgeryLow certaintySmall trials found less need for heart-supporting drugs and fewer ventricular rhythm problems after heart surgery, but no difference in hospital stay or atrial fibrillation. Muscle symptoms from statinsMixed findingsStatins lower blood CoQ10. One meta-analysis found less muscle pain with CoQ10; two others found no clear benefit, and NCCIH says the overall evidence does not support it. Blood pressureEvidence againstA Cochrane review found CoQ10 probably does not lower blood pressure by a meaningful amount (2 small trials). Migraine preventionLow certaintySix small trials found fewer and shorter attacks, but no change in severity. Some trials combined CoQ10 with other supplements. Parkinson diseaseEvidence againstA large NIH-supported trial in early Parkinson disease found no benefit and stopped for futility. NCCIH agrees. Male infertility (semen quality)Low certaintyTwo reviews found better sperm measures, but the studies were small, differed a lot, and disagree on sperm concentration. Type 2 diabetes blood-sugar markersLow certaintyA meta-analysis of 13 trials found small drops in HbA1c and fasting glucose. These are lab markers, not proof of fewer complications. Cancer treatment supportNot enough evidenceCoQ10 has not been shown to treat cancer. One small trial in children found less heart damage from one chemotherapy drug; a breast cancer trial found no gain in fatigue or quality of life.

Benefits, one by one

Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.

What CoQ10 does in the body

High certainty

Your cells make CoQ10 and use it to turn food into energy. It also works as an antioxidant in cell membranes. The most is found in the heart, liver, kidneys and pancreas, and the level falls with age.

2 studiesUbiquinone and ubiquinol are the two chemical forms; see the Science …

Studies, doses and limits

What the trials found

NCI says CoQ10 is found in most tissues, highest in the heart, liver, kidneys and pancreas, lowest in the lungs, and falls with age. No trial was read showing that extra CoQ10 raises energy in healthy people.

Results

CoQ10's jobs in cells are well established. That a supplement adds benefit for people who are not short of it is not shown by these sources.

Effect sizes as reported

No effect sizes apply: these are descriptions of body function, not trial results.

Why this rating

High that the body makes and uses CoQ10 (two government health pages). This is not a result for any supplement.

Form and dose studied

Ubiquinone and ubiquinol are the two chemical forms; see the Science part of the Evidence tab.

Who was studied

General population.

Limits

Role statements come from reference pages, not from trials.

Why researchers looked

People ask whether a supplement tops up something the body already makes.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Established physiology

CoQ10 takes part in the cell's energy chain (oxidative phosphorylation) in mitochondria, and acts as an antioxidant in membranes (MedlinePlus Genetics). This is established cell biology.

A proposed mechanism does not show that the effect happens in people.

Safety is covered in the Safety tab.

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Rare inherited CoQ10 deficiency

Not enough evidence

In a very rare inherited condition the body cannot make enough CoQ10. MedlinePlus Genetics says the brain, muscles and kidneys can be affected, that problems get worse unless treated with CoQ10 supplements, and that this should be under specialist care.

1 studiesNot compared in the sources read.

Studies, doses and limits

What the trials found

MedlinePlus Genetics estimates fewer than 1 in 100,000 people have it. It describes brain, muscle, kidney and heart effects and says the nerve problems gradually worsen unless treated with CoQ10 supplementation. No trial of this treatment was read.

Results

A recognised medical use in a very rare condition, stated by an authoritative page. It does not apply to healthy people or to ordinary tiredness.

Effect sizes as reported

No numbers read.

Why this rating

Accepted by MedlinePlus Genetics, but no trial or case series was read, so the strength of the evidence is not rated here.

Form and dose studied

Not compared in the sources read.

Who was studied

People with a confirmed inherited CoQ10 deficiency, treated by specialists.

Limits

No trial data read. Secondary (acquired) deficiency in other conditions was only mentioned, not reviewed.

Why researchers looked

It is the one clear case where a supplement replaces something the body is missing.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Established physiology

Gene changes (COQ genes) block CoQ10 production, which impairs the cell's energy chain (MedlinePlus Genetics).

A proposed mechanism does not show that the effect happens in people.

This is a specialist matter; do not self-treat.

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Food sources of CoQ10

Moderate certainty

Food gives only a few milligrams a day. Meat, fish, nuts and some oils have the most. Frying lowers the amount; boiling did not in one study.

2 studiesFood CoQ10 comes with fats, protein and other nutrients; pills are a …

Studies, doses and limits

What the trials found

A 2010 review says meat, fish, nuts and some oils are the richest sources and dairy, vegetables, fruit and cereals contain much less; average intake is about 3 to 6 mg a day. A Danish survey estimated 3 to 5 mg a day, 64% from meat and poultry, with frying destroying 14% to 32% of CoQ10. USDA FoodData Central does not list CoQ10, so no per-portion figures are given here.

Results

Typical food intake is a few milligrams a day, mostly from meat and poultry.

Effect sizes as reported

Average intake 3 to 6 mg a day (review); 3 to 5 mg a day (Danish survey).

Why this rating

Moderate: one review and one older national survey agree on the order of magnitude, but amounts vary a lot between foods and countries.

Form and dose studied

Food CoQ10 comes with fats, protein and other nutrients; pills are a different product.

Who was studied

General population.

Limits

The Danish survey is from the 1990s. Food tables for CoQ10 are patchy.

Why researchers looked

People ask whether they get CoQ10 from food and how that compares with pills.

Traditional use

Food is the everyday source besides what the body makes.

Proposed mechanism Not applicable

Not applicable; this is food composition.

A proposed mechanism does not show that the effect happens in people.

Food amounts are not a safety concern.

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Heart failure (add-on to usual care)

Moderate certainty

In people with heart failure, CoQ10 added to usual treatment was linked to fewer deaths and fewer hospital stays in several trials. The evidence is moderate at best, comes mostly from one large trial, and the Cochrane reviewers say it is not convincing.

3 studiesUbiquinone capsules were studied; trials differed in amount, length a…

Studies, doses and limits

What the trials found

Q-SYMBIO (420 people, 2 years): no change in 16-week symptom measures, but fewer major cardiovascular events (15% vs 26%) and fewer deaths. A 2021 Cochrane review of 11 trials (1,573 people) found probably fewer deaths and hospital stays (moderate quality, from 1 and 2 trials) and very uncertain effects on ejection fraction and exercise. A 2024 meta-analysis of 33 trials reported lower death and hospital stays (moderate quality) and a longer 6-minute walk.

Results

Promising for survival and hospital stays, but based on a small number of trials with risk of bias. It is an add-on to heart medicines, never a replacement.

Effect sizes as reported

Cochrane: death RR 0.58; hospital stays RR 0.62. 2024 review: death RR 0.64; hospital stays RR 0.50. Q-SYMBIO: events HR 0.50.

Why this rating

Moderate (GRADE, per the Cochrane and 2024 reviews) for death and hospital stays, very low for ejection fraction and exercise. The reviews disagree on exercise capacity.

Form and dose studied

Ubiquinone capsules were studied; trials differed in amount, length and form.

Who was studied

Adults with chronic heart failure already on standard treatment.

Limits

Most trials were small. The death result in the Cochrane review comes from one trial. Company links of the main trial are not stated in the abstract.

Why researchers looked

The heart holds a lot of CoQ10, and some studies found low CoQ10 in heart failure.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Possibly supports the heart muscle's energy supply and reduces oxidative stress (the Cochrane review lists these as proposed ideas). This was not proven in the trials read.

A proposed mechanism does not show that the effect happens in people.

Heart failure needs a cardiologist. Ask before adding any supplement, and never stop heart medicines.

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Complications after heart surgery

Low certainty

A small set of trials found that CoQ10 given before heart surgery was linked to less need for heart-supporting drugs and fewer rhythm problems. The trials were few and small.

2 studiesTrials gave CoQ10 around the operation; forms and amounts varied.

Studies, doses and limits

What the trials found

A 2015 meta-analysis of 8 trials found less need for inotropic (heart-supporting) drugs and fewer ventricular rhythm problems, but no difference in cardiac index, atrial fibrillation or hospital stay. NCCIH (2019) says there is evidence that CoQ10 may reduce the risk of some complications of heart surgery.

Results

Some signals of benefit, none for hospital stay. Surgical teams should know about every supplement.

Effect sizes as reported

Inotropes OR 0.47; ventricular arrhythmias OR 0.05 (very wide interval).

Why this rating

Low: small trials, only one database searched, and the review authors call for better trials.

Form and dose studied

Trials gave CoQ10 around the operation; forms and amounts varied.

Who was studied

Adults having heart surgery with a heart-lung machine.

Limits

Few small trials; mixed results across outcomes.

Why researchers looked

Heart surgery with a heart-lung machine stresses the heart muscle.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Proposed to protect heart cells from oxidative stress during surgery. Not proven here.

A proposed mechanism does not show that the effect happens in people.

Tell the surgical team about any supplement before an operation.

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Muscle symptoms from statin medicines

Mixed findings

Statins lower the level of CoQ10 in the blood, so people have tried CoQ10 for statin muscle pain. Reviews disagree: one found less pain, two found no clear benefit. NCCIH says the overall evidence does not support it.

5 studiesTrials used different amounts and forms.

Studies, doses and limits

What the trials found

Qu 2018 (12 trials, 575 people): less muscle pain, weakness, cramps and tiredness, but no change in blood CK. Kennedy 2020 (7 trials, 321 people): no benefit for muscle pain and no difference in staying on the statin. Banach 2015 (6 trials, 302 people): no significant effect on pain or CK. NCCIH (2019): overall evidence does not support it.

Results

Mixed. Small trials point both ways, and the more cautious reviews and NCCIH found no clear benefit. Statin muscle pain has other causes too.

Effect sizes as reported

Qu: pain WMD -1.60 (positive). Kennedy: WMD -0.42 (not significant). Banach: SMD -0.53 (not significant).

Why this rating

Mixed: three meta-analyses of small trials disagree, and NCCIH concludes the evidence does not support use.

Form and dose studied

Trials used different amounts and forms.

Who was studied

Adults on statins with muscle symptoms.

Limits

Small trials that used different symptom scales.

Why researchers looked

A 2018 meta-analysis found that statins lower blood CoQ10; its authors suggested CoQ10 supplements as a possible complementary approach.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Statin treatment lowers the level of CoQ10 in the blood (seen in trials). Whether that causes the muscle symptoms is not shown.

A proposed mechanism does not show that the effect happens in people.

Do not stop a statin without asking the prescriber. CoQ10 may interact with some medicines; see the Safety tab.

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Blood pressure

Evidence against

A Cochrane review found that CoQ10 probably does not lower blood pressure by a meaningful amount.

2 studiesNot compared.

Studies, doses and limits

What the trials found

The 2016 Cochrane review pooled 2 trials (50 people) with high blood pressure: systolic -3.68 mm Hg (95% CI -8.86 to 1.49) and diastolic -2.03 mm Hg (-4.86 to 0.81), not statistically significant. The authors rate the evidence moderate quality that there is no clinically significant effect. NCCIH (2019) agrees that CoQ10 probably has no meaningful effect.

Results

The best available evidence is against a useful blood-pressure effect, though trials are very small.

Effect sizes as reported

Systolic -3.68 mm Hg, diastolic -2.03 mm Hg, neither significant.

Why this rating

Cochrane rates the evidence moderate that there is no clinically significant effect; the pooled trials were few and small.

Form and dose studied

Not compared.

Who was studied

Adults with primary (high) blood pressure.

Limits

Only 2 trials were pooled; a third was excluded for high risk of bias.

Why researchers looked

Some early clinical trials suggested CoQ10 could lower blood pressure.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Not established

Not established.

A proposed mechanism does not show that the effect happens in people.

People on blood pressure medicines should not change them without their prescriber.

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Migraine prevention

Low certainty

A 2021 meta-analysis of six small trials found fewer and shorter migraine attacks with CoQ10, but no change in how severe attacks were. Some trials combined CoQ10 with other supplements.

1 studiesAmounts and combinations varied.

Studies, doses and limits

What the trials found

Six trials, 371 adults: frequency of attacks MD -1.52 (95% CI -2.40 to -0.65); duration MD -0.19 (-0.27 to -0.11); severity not significantly reduced.

Results

A small, mixed benefit signal for how often and how long attacks last. Results may partly come from combination products.

Effect sizes as reported

Frequency MD -1.52; duration MD -0.19; severity no significant change.

Why this rating

Low: six small trials, and some used CoQ10 together with other supplements.

Form and dose studied

Amounts and combinations varied.

Who was studied

Adults with migraine.

Limits

Small trials; combination products blur the result.

Why researchers looked

CoQ10 has been tested in small trials as a way to prevent migraine attacks.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Not established.

A proposed mechanism does not show that the effect happens in people.

Ask a doctor before adding a supplement to migraine treatment.

¹⁷

Parkinson disease

Evidence against

A large NIH-supported trial in early Parkinson disease found no benefit from CoQ10, even at very high amounts. NCCIH says the same.

2 studiesCoQ10 plus vitamin E was tested.

Studies, doses and limits

What the trials found

QE3 (600 people, up to 16 months): symptom scores worsened in all groups, slightly more with CoQ10 (placebo 6.9 points, 1,200 mg 7.5, 2,400 mg 8.0). The trial stopped early for futility. NCCIH (2019) says CoQ10 is not helpful for Parkinson symptoms.

Results

Evidence is against benefit for early Parkinson disease.

Effect sizes as reported

UPDRS worsening 6.9 vs 7.5 vs 8.0 points; p=0.49 and p=0.21 versus placebo.

Why this rating

One large, well-designed trial found no benefit and stopped for futility; NCCIH agrees.

Form and dose studied

CoQ10 plus vitamin E was tested.

Who was studied

Adults with early Parkinson disease not yet on dopamine medicine.

Limits

Early disease only; all groups also took vitamin E.

Why researchers looked

Cell and animal studies suggested CoQ10 might protect dopamine cells, and a small earlier trial hinted at benefit.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Lab animal

In lab and animal models CoQ10 reduced loss of dopamine nerve cells. This did not carry over to the human trial.

A proposed mechanism does not show that the effect happens in people.

Well tolerated in the trial; ask a neurologist before using supplements.

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Male infertility (semen quality)

Low certainty

Two recent meta-analyses found better sperm measures with CoQ10 in men with fertility problems. The studies were small and differed a lot, and they disagree on sperm concentration.

2 studiesForms and amounts varied.

Studies, doses and limits

What the trials found

A 2026 meta-analysis of 9 trials (781 men): sperm concentration +10.22 million per mL, motility +4.95 points, clinical pregnancy OR 6.02 (95% CI 1.97 to 18.41). A 2024 meta-analysis of 8 trials (877 men) found better total sperm count and motility but no significant effect on sperm concentration or semen volume.

Results

Signals of better sperm measures and possibly pregnancy, but with wide uncertainty and disagreement between reviews.

Effect sizes as reported

Concentration MD 10.22 million/mL (2026) vs not significant (2024); pregnancy OR 6.02.

Why this rating

Low: small trials, large differences between studies, some combined with other antioxidants.

Form and dose studied

Forms and amounts varied.

Who was studied

Men with unexplained or idiopathic infertility.

Limits

The two reviews disagree on concentration; pregnancy results have a very wide interval.

Why researchers looked

A 2024 review says oxidative stress in semen is a key factor in male infertility, so antioxidants such as CoQ10 have been tried.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Proposed reduction of oxidative stress in semen. Not proven.

A proposed mechanism does not show that the effect happens in people.

Fertility problems need medical assessment.

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Type 2 diabetes blood-sugar markers

Low certainty

A 2018 meta-analysis found small drops in HbA1c and fasting glucose with CoQ10 in people with type 2 diabetes. These are lab markers, not proof of fewer complications.

2 studiesAmounts and forms varied.

Studies, doses and limits

What the trials found

13 trials, 765 people: HbA1c WMD -0.29 (95% CI -0.54 to -0.03); fasting glucose WMD -11.21 (-18.99 to -3.43); fasting insulin no clear change.

Results

A small improvement in markers with mixed-quality trials.

Effect sizes as reported

HbA1c -0.29; fasting glucose -11.21 (units not given in the abstract).

Why this rating

Low: modest, mixed-quality trials and a surrogate (lab) outcome.

Form and dose studied

Amounts and forms varied.

Who was studied

Adults with type 2 diabetes.

Limits

Surrogate outcomes only; the abstract does not rate evidence certainty.

Why researchers looked

CoQ10 has been tested in trials in type 2 diabetes for blood-sugar control.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Not established

Not established.

A proposed mechanism does not show that the effect happens in people.

NCCIH says CoQ10 may interact with insulin. People on diabetes medicines should ask a pharmacist or doctor first.

^{20 23}

Cancer treatment support

Not enough evidence

CoQ10 has not been shown to treat cancer. A small trial in 20 children found it reduced heart damage from one chemotherapy drug, and a trial in breast cancer found no gain in fatigue or quality of life.

2 studiesNot compared.

Studies, doses and limits

What the trials found

NCI says few trials exist. A 236-person breast cancer trial found no improvement in fatigue or quality of life with CoQ10 plus vitamin E. A 20-child trial found less heart damage from doxorubicin. NCCIH says CoQ10 has not been shown to be of value in treating cancer but may reduce heart damage from one chemotherapy drug.

Results

Very limited evidence. It is unknown whether antioxidants change how well cancer treatment works.

Effect sizes as reported

No numbers read.

Why this rating

Insufficient: small trials, described only through NCI and NCCIH pages, and unclear what caused the benefit.

Form and dose studied

Not compared.

Who was studied

People having chemotherapy.

Limits

No long-term follow-up for effects on treatment. An observational breast cancer study linked antioxidant supplements to worse outcomes (see Safety).

Why researchers looked

People ask whether antioxidants can protect during cancer treatment.

Traditional use

CoQ10 is made by the body and is sold as a supplement. Its roles in cells are well established; that is different from showing that extra pills treat a condition.

Proposed mechanism Hypothesis

Proposed antioxidant protection of heart cells. Not established.

A proposed mechanism does not show that the effect happens in people.

Only with the oncology team's agreement.

^{24 23}

Connections to the rest of health

How Coenzyme Q10 connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.

Explore every connection: goals, body systems, organs, symptoms, genes

Kind of connection Connected to Search

A. Wellness goals

Connected to	Evidence status	Context	Studies
Cellular Protection	High certainty	What CoQ10 does in the body: Your cells make CoQ10 and use it to turn food into energy. It also works as an antioxidant in cell membranes. The most is found in the heart, liver, kidneys and pancreas, and the level falls with age.	^{24 22}
Energy And Fatigue	High certainty	What CoQ10 does in the body: Your cells make CoQ10 and use it to turn food into energy. It also works as an antioxidant in cell membranes. The most is found in the heart, liver, kidneys and pancreas, and the level falls with age.	^{24 22}
Cellular Protection	Not enough evidence	Rare inherited CoQ10 deficiency: In a very rare inherited condition the body cannot make enough CoQ10. MedlinePlus Genetics says the brain, muscles and kidneys can be affected, that problems get worse unless treated with CoQ10 supplements, and that this should be under specialist care.	²²
Balanced Nutrition	Moderate certainty	Food sources of CoQ10: Food gives only a few milligrams a day. Meat, fish, nuts and some oils have the most. Frying lowers the amount; boiling did not in one study.	^{13 18}
Heart Health	Moderate certainty	Heart failure (add-on to usual care): In people with heart failure, CoQ10 added to usual treatment was linked to fewer deaths and fewer hospital stays in several trials. The evidence is moderate at best, comes mostly from one large trial, and the Cochrane reviewers say it is not convincing. Complications after heart surgery: A small set of trials found that CoQ10 given before heart surgery was linked to less need for heart-supporting drugs and fewer rhythm problems. The trials were few and small.	^{2 11 19 21 23 15 9 4 16 8}
Muscle Health	Mixed findings	Muscle symptoms from statin medicines: Statins lower the level of CoQ10 in the blood, so people have tried CoQ10 for statin muscle pain. Reviews disagree: one found less pain, two found no clear benefit. NCCIH says the overall evidence does not support it.	^{15 9 4 16 23}
Pain Relief	Low certainty	Migraine prevention: A 2021 meta-analysis of six small trials found fewer and shorter migraine attacks with CoQ10, but no change in how severe attacks were. Some trials combined CoQ10 with other supplements.	¹⁷
Brain Health	Evidence against	Parkinson disease: A large NIH-supported trial in early Parkinson disease found no benefit from CoQ10, even at very high amounts. NCCIH says the same.	^{12 23}
Fertility And Sexual Health	Low certainty	Male infertility (semen quality): Two recent meta-analyses found better sperm measures with CoQ10 in men with fertility problems. The studies were small and differed a lot, and they disagree on sperm concentration.	^{3 1}
Blood Sugar Support	Low certainty	Type 2 diabetes blood-sugar markers: A 2018 meta-analysis found small drops in HbA1c and fasting glucose with CoQ10 in people with type 2 diabetes. These are lab markers, not proof of fewer complications.	^{20 23}
Cancer Support	Not enough evidence	Cancer treatment support: CoQ10 has not been shown to treat cancer. A small trial in 20 children found it reduced heart damage from one chemotherapy drug, and a trial in breast cancer found no gain in fatigue or quality of life.	^{24 23}

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Whole Body	Biological association	High certainty	Studied for: What CoQ10 does in the body Studied for: Food sources of CoQ10	^{24 22 13 18}
Cardiovascular System	Biological association	High certainty	Studied for: What CoQ10 does in the body Studied for: Heart failure (add-on to usual care)	^{24 22 2 11 19 21 23 15 9 4 16 8}
Nervous System	Biological association	Not enough evidence	Studied for: Rare inherited CoQ10 deficiency Studied for: Migraine prevention	^{22 17 12 23}
Kidneys	Biological association	Not enough evidence	Studied for: Rare inherited CoQ10 deficiency	²²
Muscles	Biological association	Not enough evidence	Studied for: Rare inherited CoQ10 deficiency Studied for: Muscle symptoms from statin medicines	^{22 15 9 4 16 23}
Reproductive System	Biological association	Low certainty	Studied for: Male infertility (semen quality)	^{3 1}
Metabolism	Biological association	Low certainty	Studied for: Type 2 diabetes blood-sugar markers	^{20 23}

E. Health conditions

Connected to	Kind of connection	Evidence status	Context	Studies
Heart failure		Clinical trial evidence	Fewer deaths and hospital stays as an add-on in reviews; evidence not convincing per Cochrane. Preparation or compound: Ubiquinone supplements	^{2 19}

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
Death from any cause (heart failure)	Biological association	Moderate certainty	Measured in trials: fewer deaths in trials. A lab change is not the same as a health benefit.	^{2 19 11}
Hospital stays for heart failure	Biological association	Moderate certainty	Measured in trials: fewer stays in trials. A lab change is not the same as a health benefit.	^{2 19}
Heart pumping strength (ejection fraction)	Biological association	Very low certainty	Measured in trials: small rise. A lab change is not the same as a health benefit.	^{2 19}
Muscle pain score on a statin	Biological association	Mixed findings	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{15 9 4}
Blood creatine kinase (CK)	Biological association	Low certainty	Measured in trials: no change. A lab change is not the same as a health benefit.	^{15 4}
CoQ10 level in the blood during statin treatment	Biological association	Moderate certainty	Measured in trials: lower with statins. A lab change is not the same as a health benefit.	¹⁶
Systolic blood pressure	Biological association	Evidence against	Measured in trials: no meaningful change. A lab change is not the same as a health benefit.	⁸
Migraine attacks per month	Biological association	Low certainty	Measured in trials: fewer. A lab change is not the same as a health benefit.	¹⁷
Parkinson symptom score (UPDRS)	Biological association	Evidence against	Measured in trials: no benefit. A lab change is not the same as a health benefit.	¹²
Sperm motility	Biological association	Low certainty	Measured in trials: higher. A lab change is not the same as a health benefit.	^{3 1}
Sperm concentration	Biological association	Mixed findings	Measured in trials: mixed. A lab change is not the same as a health benefit.	^{3 1}
Clinical pregnancy	Biological association	Low certainty	Measured in trials: higher in one review. A lab change is not the same as a health benefit.	³
HbA1c	Biological association	Low certainty	Measured in trials: small drop. A lab change is not the same as a health benefit.	²⁰

J. Genes, receptors and enzymes

Connected to	Kind of connection	Evidence status	Context	Studies
COQ genes (COQ2, COQ4, COQ6, COQ8A, COQ8B)	Preliminary mechanism	Human	Mutations cause primary CoQ10 deficiency.	²²

K. Biological pathways

Connected to	Kind of connection	Evidence status	Context	Studies
Statins	Preliminary mechanism	Human	Lower blood CoQ10 in trials.	¹⁶

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
Ubiquinone	Biological association	Human	The standard supplement form, studied in the heart failure and Parkinson trials. In a 2020 single-dose study, ubiquinone capsules were absorbed less than a water-soluble syrup.	^{11 12 14}
Ubiquinol	Biological association	Human	In a 12-person study blood CoQ10 rose more after ubiquinol than after ubiquinone; a larger crossover in 21 older adults found no significant difference.	^{10 14}

Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 26, 2026).

Evidence at a glance: what changed in 2 lab markers

Tap a number to show only those markers. Counts are markers, not people.

Other2

The evidence

The research centre for Coenzyme Q10. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

What CoQ10 does in the body 2 studies High certainty Rare inherited CoQ10 deficiency 1 study Not enough evidence Food sources of CoQ10 2 studies Moderate certainty Heart failure (add-on to usual care) 3 studies Moderate certainty Complications after heart surgery 2 studies Low certainty Muscle symptoms from statin medicines 5 studies Mixed findings Blood pressure 2 studies Evidence against Migraine prevention 1 study Low certainty Parkinson disease 2 studies Evidence against Male infertility (semen quality) 2 studies Low certainty Type 2 diabetes blood-sugar markers 2 studies Low certainty Cancer treatment support 2 studies Not enough evidence

Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).

How we rate evidence

High certainty

Several well-run trials or reviews agree; further research is unlikely to change the picture much.

Moderate certainty

Good trials point the same way, but some doubt remains.

Low certainty

Small, short or inconsistent trials. The finding could change with better research.

Very low certainty

Very little or very weak human data. Treat as a possibility only.

Mixed findings

Trials or reviews disagree with each other.

Not enough evidence

Not enough human research to say either way.

Evidence against

Good research found no benefit, or found harm.

We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We started from our existing summary, read the NCCIH, NCI and MedlinePlus Genetics pages, and re-read PubMed abstracts for reviews and trials. Only abstracts were read for studies. The NIH Office of Dietary Supplements page was blocked and is marked unread.

Study library: every study we checked 25

Design Research type Year from Search

Study	Design	People	Product, dose, length	Result
Akhigbe 2024 Does coenzyme Q10 improve semen quality and circulating testosterone level? a systematic review and meta-analysis of randomized controlled trials. Front Pharmacol · PMID 39830337 · DOI	Systematic review meta analysis	877 Men with fertility problems; 8 randomised trials	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Untreated or placebo	Higher total sperm count, motility and normal-shaped sperm, and higher testosterone. No significant effect on semen volume or sperm concentration. The authors note large differences between the studies. No significant effect on sperm concentration or semen volume; other measures improved (Sperm concentration SMD -6.69 (-16.28 to 2.90), not significant) Methods, limits and funding Outcomes: Sperm count, motility, normal shape, semen volume, sperm concentration, hormones Limitations: Large differences between studies for the semen results. Its finding of no effect on sperm concentration differs from the 2026 meta-analysis. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Al Saadi 2021 Coenzyme Q10 for heart failure. Cochrane Database Syst Rev · PMID 35608922 · DOI	Systematic review meta analysis	1573 11 randomised trials in people with heart failure; most were small	Coenzyme Q10 (ubiquinone) by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Placebo or usual treatment	Probably fewer deaths and fewer hospital stays for heart failure (moderate-quality evidence, but each from only 1 or 2 trials). Effects on ejection fraction and exercise were very uncertain. The authors say there is no convincing evidence either way. All-cause death RR 0.58 (1 trial, 420 people); heart-failure hospital stays RR 0.62 (2 trials, 1,061 people); ejection fraction MD 1.77 points (7 trials, 650 people, very low quality) (Death RR 0.58 (0.35 to 0.95); hospital stays RR 0.62 (0.49 to 0.78); ejection fraction MD 1.77 (0.09 to 3.44); side effects RR 0.70 (0.45 to 1.10)) Methods, limits and funding Outcomes: Death from any cause; hospital stays for heart failure; heart pumping measure (ejection fraction); exercise capacity; side effects Limitations: All trials had unclear or high risk of bias. The death result comes from a single trial. No trial measured quality of life with a validated scale. Funding and conflicts: No conflicts stated in the abstract; Cochrane review. Read: abstract
Bakri 2026 Efficacy and Safety of Coenzyme Q10 in Idiopathic Male Infertility: A Systematic Review and Meta-Analysis of Randomized Trials. World J Mens Health · PMID 40878114 · DOI	Systematic review meta analysis	781 Men with unexplained (idiopathic) infertility; 9 randomised trials	Coenzyme Q10 by mouth, alone or with other antioxidants Oral supplement Differed between trials (not compared here) Often over 3 months · vs Placebo or other therapy	Better sperm concentration, motility and volume, and more clinical pregnancies, especially with treatment longer than 3 months. Three studies reported no side effects; one reported mild, passing ones. Sperm concentration MD 10.22 million per mL; motility MD 4.95 percentage points; clinical pregnancy OR 6.02 (Concentration 3.51 to 16.93; motility 1.15 to 8.75; pregnancy 1.97 to 18.41) Methods, limits and funding Outcomes: Sperm concentration, motility, semen volume, clinical pregnancy Limitations: Small trials and a wide range of pregnancy results. Some trials added other antioxidants. The abstract does not rate the certainty of the evidence. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Banach 2015 Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials. Mayo Clin Proc · PMID 25440725 · DOI	Systematic review meta analysis	302 Adults on statin therapy (6 randomised trials)	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Control	No significant effect on muscle pain (a trend towards less pain) and no significant change in CK. The authors say larger, better trials are needed. Muscle pain SMD -0.53 (not significant); CK +11.69 U/L (not significant) (Muscle pain -1.33 to 0.28; CK -14.25 to 37.63) Methods, limits and funding Outcomes: Muscle pain; blood creatine kinase (CK) Limitations: Small trials, few people. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Engelsen 2003 Effect of Coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial. Ugeskr Laeger · PMID 12772396	Randomised controlled trial	24 Adults on stable, long-term warfarin (blood thinner); 21 completed	Coenzyme Q10 (and, in other periods, ginkgo) Oral supplement 100 mg a day (studied in the trial) 4 weeks per period, 2-week washout · vs Placebo	The warfarin dose and the INR stayed stable on CoQ10: the authors concluded CoQ10 did not change warfarin's clinical effect in this small trial. Warfarin about 36.5 mg a week on CoQ10 vs 36.0 mg on placebo (CoQ10 29.1 to 45.8; placebo 28.6 to 45.1 mg a week) Methods, limits and funding Outcomes: Warfarin dose needed to keep INR between 2.0 and 4.0 Limitations: A small, short crossover trial in people already stable on warfarin. It does not rule out effects in other people or at other amounts. An English-abstract report of a Danish-language paper; a letter version appeared in Thromb Haemost 2002 (PMID 12083489, no abstract available). Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Hathcock 2006 Risk assessment for coenzyme Q10 (Ubiquinone). Regul Toxicol Pharmacol · PMID 16814438 · DOI	Narrative review	Review of clinical trials of CoQ10 for a safety (risk) assessment	Coenzyme Q10 Oral supplement	Stomach and gut complaints could not be linked to CoQ10 because they were no more common at higher intakes than at lower ones. The authors set an "observed safe level" of 1,200 mg a day and say data above that are too thin to judge. Observed safe level 1,200 mg a day (the authors' own estimate) (Not applicable) Methods, limits and funding Outcomes: Side effects and a safe-intake estimate Limitations: A published risk assessment by the authors, not a regulator's limit. It is not advice to take any amount. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Hidaka 2008 Safety assessment of coenzyme Q10 (CoQ10). BioFactors · PMID 19096117 · DOI	Narrative review	Review of animal and human safety data on CoQ10	Coenzyme Q10 Oral supplement	CoQ10 showed low toxicity and no serious side effects in humans. The authors calculated an acceptable daily intake from a 52-week rat study and agree with the same 1,200 mg a day observed safe level. They also say CoQ10 does not build up in blood or tissues after stopping. Authors' calculated acceptable daily intake 12 mg per kg of body weight; observed safe level 1,200 mg a day (Not applicable) Methods, limits and funding Outcomes: Toxicity and safety Limitations: A published review, not a regulator's limit. Part of the basis is a rat study. Several authors may have industry links; the abstract does not state funding. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Ho 2016 Blood pressure lowering efficacy of coenzyme Q10 for primary hypertension. Cochrane Database Syst Rev · PMID 26935713 · DOI	Systematic review meta analysis	50 Adults with primary (high) blood pressure; 3 trials found, 2 pooled (50 people)	Coenzyme Q10 by mouth Oral supplement At least 3 weeks · vs Placebo	No clinically significant change in blood pressure. In one of three trials that reported side effects, CoQ10 was well tolerated. Systolic -3.68 mm Hg; diastolic -2.03 mm Hg (neither significant) (Systolic -8.86 to 1.49; diastolic -4.86 to 0.81) Methods, limits and funding Outcomes: Blood pressure (clinic readings) Limitations: Very few small trials; one trial was left out for high risk of bias. Funding and conflicts: No conflicts stated in the abstract; Cochrane review. Read: abstract
Kennedy 2020 Effect of Coenzyme Q10 on statin-associated myalgia and adherence to statin therapy: A systematic review and meta-analysis. Atherosclerosis · PMID 32179207 · DOI	Systematic review meta analysis	321 Adults with statin-associated muscle pain (7 randomised trials in the pooled result, 37 to 76 people each)	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Placebo	No benefit for muscle pain and no difference in how many people stayed on their statin. Only 2 of the 8 trials found a benefit. Muscle pain WMD -0.42 (not significant); staying on statin RR 0.99 (Muscle pain -1.47 to 0.62; staying on statin 0.81 to 1.20) Methods, limits and funding Outcomes: Muscle pain symptoms; staying on the statin Limitations: Small trials; a few hundred people in total. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Langsjoen 2014 Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone. Clin Pharmacol Drug Dev · PMID 27128225 · DOI	Crossover study	12 Twelve healthy volunteers	Ubiquinone versus ubiquinol (same capsule base) Soft-gel capsule 200 mg a day each (studied in the trial) 4 weeks each, 4-week washout · vs Each person was their own comparison	Blood CoQ10 rose more after ubiquinol than after ubiquinone (4.3 vs 2.5 µg/mL from a baseline of 0.9). No side effects noted. Plasma total CoQ10 4.3 µg/mL (ubiquinol) vs 2.5 µg/mL (ubiquinone) (p<0.005 for the difference) Methods, limits and funding Outcomes: Blood CoQ10 level Limitations: Twelve healthy people took ubiquinone first and then ubiquinol, so an order effect is possible. No clinical outcomes were measured. Blood level is not the same as benefit. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Mortensen 2014 The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO: a randomized double-blind trial. JACC Heart Fail · PMID 25282031 · DOI	Randomised controlled trial	420 Adults with moderate to severe chronic heart failure, in addition to standard treatment	Coenzyme Q10 (ubiquinone) Oral supplement 100 mg three times a day (studied in the trial) 2 years · vs Placebo	No significant change in the 16-week measures. Over 2 years, fewer major cardiovascular events (15% vs 26%), and fewer deaths from any cause (10% vs 18%) and hospital stays for heart failure. Major adverse cardiovascular events 15% vs 26%, HR 0.50; all-cause death 10% vs 18% (p=0.018) (HR 0.50 (0.32 to 0.80), p=0.003) Methods, limits and funding Outcomes: Short-term (16 weeks): symptom class, 6-minute walk, NT-proBNP. Long-term (2 years): major adverse cardiovascular events Limitations: One trial. The death result was a secondary outcome. Funding and any company links are not stated in the abstract. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Parkinson Study Group QE3 Investigators 2014 A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit. JAMA Neurol · PMID 24664227 · DOI	Randomised controlled trial	600 Adults with early Parkinson disease who did not yet need Parkinson medicine, 67 North American sites	Coenzyme Q10 (all groups also took vitamin E) Oral supplement 1,200 or 2,400 mg a day (studied in the trial, with vitamin E 1,200 IU) Up to 16 months · vs Placebo	No benefit. Scores worsened in every group, slightly more with CoQ10. The trial was stopped early for futility. CoQ10 was well tolerated. UPDRS worsening: placebo 6.9; 1,200 mg 7.5 (p=0.49); 2,400 mg 8.0 (p=0.21) (p-values only in the abstract) Methods, limits and funding Outcomes: Change in total UPDRS score (a Parkinson symptom score; higher = worse) Limitations: Early disease only; the result does not cover later Parkinson disease. It tested very high amounts together with vitamin E. Funding and conflicts: NIH-supported trial (the abstract lists NIH extramural support); NCT00740714. Read: abstract
Pravst 2010 Coenzyme Q10 contents in foods and fortification strategies. Crit Rev Food Sci Nutr · PMID 20301015 · DOI	Narrative review	Review of published measurements of CoQ10 in foods	CoQ10 in foods Foods	Meat, fish, nuts and some oils are the richest food sources. Dairy, vegetables, fruit and cereals have much less. Average dietary intake is about 3 to 6 mg a day, around half of it in the reduced form. Average dietary intake 3 to 6 mg a day (Not applicable) Methods, limits and funding Outcomes: Which foods contain CoQ10 and how much is eaten Limitations: Narrative review; amounts vary a lot between foods and countries. The abstract gives no per-portion numbers. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Pravst 2020 Comparative Bioavailability of Different Coenzyme Q10 Formulations in Healthy Elderly Individuals. Nutrients · PMID 32188111 · DOI	Randomised crossover trial	21 Healthy adults aged 65 to 74	Ubiquinone capsule, ubiquinol capsule and a water-soluble CoQ10 syrup (a branded test product) Capsule and syrup 100 mg CoQ10 equivalent, single dose (studied in the trial) Single dose, 48 hours of blood sampling · vs Ubiquinone capsule (standard)	The water-soluble syrup gave 2.4 times the absorption of the ubiquinone capsule. Ubiquinol was not significantly better (1.7-fold). CoQ10 appeared in the blood mostly as ubiquinol even when ubiquinone was swallowed. Syrup 2.4-fold (p=0.002); ubiquinol 1.7-fold (p=0.129) vs ubiquinone (Syrup 1.3 to 4.5; ubiquinol 0.9 to 3.1) Methods, limits and funding Outcomes: Blood CoQ10 over 48 hours (AUC) Limitations: Single dose in 21 healthy people. The test product is a branded formulation, so a link to its maker is possible; the abstract does not state funding. Blood level is not the same as benefit. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Qu 2018 Effects of Coenzyme Q10 on Statin-Induced Myopathy: An Updated Meta-Analysis of Randomized Controlled Trials. J Am Heart Assoc · PMID 30371340 · DOI	Systematic review meta analysis	575 Adults taking statins with muscle symptoms (12 randomised trials)	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Placebo	Lower scores for muscle pain, weakness, cramps and tiredness with CoQ10, but no change in blood CK. Muscle pain WMD -1.60; CK WMD 0.09 (no change) (Muscle pain -1.75 to -1.44; CK -0.06 to 0.24) Methods, limits and funding Outcomes: Muscle pain, weakness, cramps, tiredness; blood creatine kinase (CK, a muscle-damage marker) Limitations: Pooled small trials that used different symptom scales. Its result disagrees with two other meta-analyses of the same question (Banach 2015, Kennedy 2020). Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Qu 2018 The effect of statin treatment on circulating coenzyme Q10 concentrations: an updated meta-analysis of randomized controlled trials. Eur J Med Res · PMID 30414615 · DOI	Systematic review meta analysis	1776 12 randomised trials of statins (versus placebo) that measured blood CoQ10	Statin medicines (not a CoQ10 supplement) Differed between trials · vs Placebo	Statin treatment lowered the level of CoQ10 in the blood. The authors suggest this may be one reason for statin muscle symptoms. That link was not tested in this study. Blood CoQ10 SMD -2.12 with statins (-3.40 to -0.84) Methods, limits and funding Outcomes: Level of CoQ10 in the blood Limitations: Measures blood levels only; it does not show that low blood CoQ10 causes muscle symptoms or that supplements fix them. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Sazali 2021 Coenzyme Q10 supplementation for prophylaxis in adult patients with migraine-a meta-analysis. BMJ Open · PMID 33402403 · DOI	Systematic review meta analysis	371 Adults with migraine (6 randomised trials; some used CoQ10 together with other supplements)	Coenzyme Q10 by mouth, alone or combined Oral supplement Differed between trials (not compared here) Differed between trials · vs Placebo or other treatment	No significant reduction in severity. Fewer attacks and shorter attacks with CoQ10. Frequency MD -1.52 attacks (units as in the trials); duration MD -0.19 (units not given in the abstract) (Frequency -2.40 to -0.65; duration -0.27 to -0.11) Methods, limits and funding Outcomes: Severity, frequency and duration of migraine attacks Limitations: Six small trials. Some combined CoQ10 with other supplements, so the result is not for CoQ10 alone. Severity did not improve. Funding and conflicts: Funding is not stated in the abstract; PROSPERO CRD42019126127. Read: abstract
Weber 1997 The coenzyme Q10 content of the average Danish diet. Int J Vitam Nutr Res · PMID 9129255	Dietary survey	Danish national diet survey with laboratory analysis of foods	CoQ10 in foods Foods	Average intake was estimated at 3 to 5 mg a day, mostly (64%) from meat and poultry. Frying destroyed 14% to 32% of the CoQ10; boiling destroyed no detectable amount. Intake 3 to 5 mg a day; frying loss 14% to 32% (Not applicable) Methods, limits and funding Outcomes: CoQ10 intake from food; effect of cooking Limitations: Danish diet in the 1990s; other countries and today's diets may differ. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
Xu 2024 Efficacy and safety of coenzyme Q10 in heart failure: a meta-analysis of randomized controlled trials. BMC Cardiovasc Disord · PMID 39462324 · DOI	Systematic review meta analysis	33 randomised trials in people with heart failure	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Control (placebo or usual care)	Lower death and hospital stays (moderate quality); lower BNP and symptom class and a little better ejection fraction (low quality); longer walk distance (moderate quality). The authors report no major side effects. All-cause death RR 0.64; heart-failure hospital stays RR 0.50; 6-minute walk +31.7 (units not given in the abstract); ejection fraction +0.51 (Death RR 0.64 (0.48 to 0.85); hospital stays RR 0.50 (0.37 to 0.67); 6-minute walk MD 31.70 (19.96 to 43.43); ejection fraction MD 0.51 (0.31 to 0.71)) Methods, limits and funding Outcomes: Death, hospital stays, symptom class (NYHA), BNP blood marker, ejection fraction, 6-minute walk Limitations: Pooled many small trials of differing quality. Its walk-test result is more positive than the Cochrane review, which found exercise capacity inconclusive. Funding and conflicts: No funding or conflicts stated in the abstract; PROSPERO CRD42023493184. Read: abstract
Zhang 2018 Effectiveness of Coenzyme Q10 Supplementation for Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. Int J Endocrinol · PMID 30305810 · DOI	Systematic review meta analysis	765 Adults with type 2 diabetes; 13 randomised trials	Coenzyme Q10 by mouth Oral supplement Differed between trials (not compared here) Differed between trials · vs Placebo or usual medicine	Small drops in HbA1c and fasting glucose; no clear change in fasting insulin. The authors say CoQ10 "may assist" blood-sugar control. HbA1c WMD -0.29; fasting glucose WMD -11.21 (units not given in the abstract); insulin no change (HbA1c -0.54 to -0.03; glucose -18.99 to -3.43; insulin -2.54 to 1.57) Methods, limits and funding Outcomes: HbA1c, fasting blood glucose, fasting insulin Limitations: Small trials of mixed quality; the abstract does not give a certainty rating. These are blood-test markers, not diabetes complications. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
de Frutos 2015 Prophylactic treatment with coenzyme Q10 in patients undergoing cardiac surgery: could an antioxidant reduce complications? A systematic review and meta-analysis. Interact Cardiovasc Thorac Surg · PMID 25344142 · DOI	Systematic review meta analysis	Adults having heart surgery with a heart-lung machine; 8 clinical trials	Coenzyme Q10 given before surgery Oral or injected (as in the trials) Differed between trials (not compared here) Differed between trials · vs Control	Less need for inotropic (heart-supporting) drugs and fewer ventricular rhythm problems. No effect on cardiac index, atrial fibrillation or hospital stay. None of the trials reported side effects. Inotropes OR 0.47; ventricular arrhythmias OR 0.05 (Inotropes 0.27 to 0.81; arrhythmias 0.01 to 0.31) Methods, limits and funding Outcomes: Need for heart-supporting drugs, abnormal heart rhythms, cardiac index, hospital stay Limitations: Only PubMed was searched; the trials were few and small, and the authors call for better trials. Funding and conflicts: Funding is not stated in the abstract. Read: abstract
s-medlineplus-coq10-deficiency MedlinePlus Genetics: Primary coenzyme Q10 deficiency · Source	Reference database n/a			Methods, limits and funding Read: full-text
s-nccih-coq10 NCCIH: Coenzyme Q10 (Last Updated January 2019) · Source	Reference database n/a			Methods, limits and funding Read: full-text
s-nci-coq10 National Cancer Institute: Coenzyme Q10 (PDQ), Patient Version · Source	Reference database n/a			Methods, limits and funding Read: full-text
s-ods-coq10 NIH Office of Dietary Supplements: Coenzyme Q10 fact sheet · Source	Reference database n/a			Methods, limits and funding Read: not-read

What we do not know yet

No large modern trial confirming the Q-SYMBIO heart failure result was read.
Safety in pregnancy, breastfeeding and children was not found in the sources read.
The NIH Office of Dietary Supplements fact sheet could not be read, so no official upper limit is stated.
Ubiquinol versus ubiquinone: the two absorption studies read disagree.
Contamination and label accuracy of products were not researched.
Fibromyalgia, kidney disease, gum disease and skin ageing were not researched here.

How new research is added

New studies are found by a saved PubMed search and placed in a review queue before the page changes.

Lab markers

What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".

Metabolic 1

●

HbA1c

Small drop in trials

The average blood sugar over about three months.

Low certainty

Results and what it means

Why it was measured

To see whether CoQ10 changes long-term blood sugar in diabetes.

Statistical vs. clinical meaning

A small change in a lab marker.

Safety implication

Ask a doctor if on insulin or diabetes pills.

Study	Result	People	Product
²⁰	WMD -0.29 (95% CI -0.54 to -0.03)	13 trials, 765 people with type 2 diabetes	CoQ10

²⁰

Other 12

●

Death from any cause (heart failure)

Fewer deaths in trials in trials

Whether a person with heart failure died during follow-up.

Moderate certainty

Results and what it means

Why it was measured

To see whether CoQ10 added to usual care changes survival.

Statistical vs. clinical meaning

A meaningful result but drawn from few trials with risk of bias.

Safety implication

No serious safety signal in the trials read; see the Safety tab.

Study	Result	People	Product
²	RR 0.58 (95% CI 0.35 to 0.95), one trial, moderate-quality evidence	420 people with heart failure (Q-SYMBIO)	CoQ10 added to usual care
¹⁹	RR 0.64 (95% CI 0.48 to 0.85), moderate GRADE	33 trials	CoQ10 by mouth

^{2 19 11}

●

Hospital stays for heart failure

Fewer stays in trials in trials

How often people were admitted to hospital because heart failure got worse.

Moderate certainty

Results and what it means

Why it was measured

To see whether CoQ10 changes how often people need hospital care.

Statistical vs. clinical meaning

Consistent in both reviews, but only two trials contributed to the Cochrane result.

Safety implication

No serious safety signal in the trials read.

Study	Result	People	Product
²	RR 0.62 (95% CI 0.49 to 0.78), moderate-quality evidence	2 trials, 1,061 people	CoQ10 added to usual care
¹⁹	RR 0.50 (95% CI 0.37 to 0.67), moderate GRADE	33 trials	CoQ10 by mouth

^{2 19}

●

Heart pumping strength (ejection fraction)

Small rise in trials

The share of blood the heart pushes out with each beat.

Very low certainty

Results and what it means

Why it was measured

A common measure of heart failure severity.

Statistical vs. clinical meaning

Tiny changes of doubtful clinical meaning and low-quality evidence.

Safety implication

None noted.

Study	Result	People	Product
²	MD +1.77 points (95% CI 0.09 to 3.44), very low quality	7 trials, 650 people	CoQ10 by mouth
¹⁹	MD +0.51 (95% CI 0.31 to 0.71), low GRADE	33 trials	CoQ10 by mouth

^{2 19}

↕

Muscle pain score on a statin

Mixed results in trials

A symptom score for muscle pain in people taking statins.

Mixed findings

Results and what it means

Why it was measured

To see whether CoQ10 eases statin muscle pain.

Statistical vs. clinical meaning

Three meta-analyses disagree; the two more cautious ones found no clear benefit.

Safety implication

Do not stop a statin without asking the prescriber.

Study	Result	People	Product
¹⁵	WMD -1.60 (95% CI -1.75 to -1.44)	12 trials, 575 people	CoQ10 by mouth
⁹	WMD -0.42 (95% CI -1.47 to 0.62), not significant	7 trials, 321 people	CoQ10 by mouth
⁴	SMD -0.53 (95% CI -1.33 to 0.28), not significant	5 trials, 253 people	CoQ10 by mouth

^{15 9 4}

●

Blood creatine kinase (CK)

No change in trials

A blood marker of muscle damage.

Low certainty

Results and what it means

Why it was measured

To see whether CoQ10 changes a lab sign of muscle damage in statin users.

Statistical vs. clinical meaning

Both reviews found no change in CK.

Safety implication

None noted.

Study	Result	People	Product
¹⁵	WMD 0.09 (95% CI -0.06 to 0.24), no change	12 trials	CoQ10 by mouth
⁴	MD +11.69 U/L (95% CI -14.25 to 37.63), no change	5 trials, 226 people	CoQ10 by mouth

^{15 4}

●

CoQ10 level in the blood during statin treatment

Lower with statins in trials

How much CoQ10 circulates in the blood.

Moderate certainty

Results and what it means

Why it was measured

To see whether statins lower the body's CoQ10.

Statistical vs. clinical meaning

Statins lowered blood CoQ10 in the pooled trials; this does not show that muscle symptoms are caused by low CoQ10.

Safety implication

Not applicable.

Study	Result	People	Product
¹⁶	SMD -2.12 (95% CI -3.40 to -0.84)	12 trials, 1,776 people	Statin medicines versus placebo (no CoQ10 supplement)

¹⁶

●

Systolic blood pressure

No meaningful change in trials

The top number of a blood pressure reading.

Evidence against

Results and what it means

Why it was measured

To see whether CoQ10 lowers blood pressure.

Statistical vs. clinical meaning

Cochrane: moderate-quality evidence of no clinically significant effect.

Safety implication

None noted.

Study	Result	People	Product
⁸	-3.68 mm Hg (95% CI -8.86 to 1.49), not significant	2 trials, 50 people	CoQ10 by mouth

⁸

●

Migraine attacks per month

Fewer in trials

How often migraine attacks occur.

Low certainty

Results and what it means

Why it was measured

To see whether CoQ10 reduces attacks.

Statistical vs. clinical meaning

Small trials, combination products.

Safety implication

Not applicable.

Study	Result	People	Product
¹⁷	MD -1.52 (95% CI -2.40 to -0.65)	6 trials, 371 adults	CoQ10, some combined with other supplements

¹⁷

●

Parkinson symptom score (UPDRS)

No benefit in trials

A clinical rating of Parkinson symptoms; higher means worse.

Evidence against

Results and what it means

Why it was measured

To see whether CoQ10 slows Parkinson progression.

Statistical vs. clinical meaning

Large trial stopped for futility.

Safety implication

Well tolerated in the trial.

Study	Result	People	Product
¹²	Worsening 6.9 (placebo), 7.5 (1,200 mg), 8.0 (2,400 mg); neither significant	600 adults with early Parkinson disease	CoQ10 plus vitamin E

¹²

●

Sperm motility

Higher in trials

The share of sperm that move normally.

Low certainty

Results and what it means

Why it was measured

To see whether CoQ10 improves semen quality.

Statistical vs. clinical meaning

Both reviews agree on direction; heterogeneity is high.

Safety implication

No serious effects reported.

Study	Result	People	Product
³	MD +4.95% (95% CI 1.15 to 8.75)	9 trials, 781 men	CoQ10
¹	Higher total and progressive motility reported; large differences between studies	8 trials, 877 men	CoQ10

^{3 1}

↕

Sperm concentration

Mixed results in trials

Sperm count per mL of semen.

Mixed findings

Results and what it means

Why it was measured

To see whether CoQ10 raises sperm count.

Statistical vs. clinical meaning

The two reviews disagree.

Safety implication

Not applicable.

Study	Result	People	Product
³	MD +10.22 million/mL (95% CI 3.51 to 16.93)	9 trials, 781 men	CoQ10
¹	No significant effect (SMD -6.69, 95% CI -16.28 to 2.90)	8 trials, 877 men	CoQ10

^{3 1}

●

Clinical pregnancy

Higher in one review in trials

Whether a partner became pregnant during the study.

Low certainty

Results and what it means

Why it was measured

The outcome that matters most for fertility.

Statistical vs. clinical meaning

A very wide interval from few small trials.

Safety implication

Not applicable.

Study	Result	People	Product
³	OR 6.02 (95% CI 1.97 to 18.41)	9 trials, 781 men	CoQ10

Safety

What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.

Main points to know 4

Possible blood-thinner (warfarin) and insulin interactions. NCCIH and NCI both say CoQ10 may change how the body uses warfarin and insulin. A small 2003 trial in 21 people stable on warfarin found no change in warfarin dose or INR with CoQ10 for 4 weeks, so the evidence is mixed. Anyone on warfarin or insulin should ask a pharmacist or doctor first. Authoritative guidance and small trial ^{23 24 5}
Cancer treatment: check with the cancer team. NCI says trials of CoQ10 during chemotherapy or radiation did not follow people long enough to know whether it made treatment less effective. A recent observational study in breast cancer suggested antioxidant supplements, including CoQ10, before and during treatment may be linked to more recurrence and lower survival. Observational studies cannot prove cause. NCCIH says CoQ10 may not be compatible with some cancer treatments. Authoritative guidance (observational study described, not read) ^{24 23}
Usually mild side effects. NCCIH says no serious side effects have been reported; mild ones such as insomnia or stomach upset can occur. NCI lists raised liver enzymes, nausea, heartburn, headache, upper stomach pain, dizziness, rashes, trouble sleeping, tiredness, irritability and sensitivity to light. Authoritative guidance ^{23 24 6}
Quality of supplements can differ. NCI says the FDA does not regularly review how supplements are made, so batches and brands of CoQ10 may not be the same. Authoritative guidance ²⁴

Side effects 4

Effect	How often	Severity and recovery	Evidence
Stomach and gut upset (nausea, heartburn, upper stomach pain) In the heart failure trials, the Cochrane review found side effects were similar or fewer with CoQ10 (RR 0.70, 95% CI 0.45 to 1.10; very low quality).	A 2006 safety review found these were no more common at higher amounts than at lower ones, so they could not be linked directly to CoQ10. No rate was found.	Mild Not stated in the sources read.	Review and authoritative guidance ^{6 24 23}
Trouble sleeping, tiredness, irritability, dizziness, headache	Not given.	Mild for insomnia (NCCIH); others not rated in the source Not stated.	Authoritative guidance ^{23 24}
Rash and light sensitivity	Not given.	Not rated in the source Not stated.	Authoritative guidance ²⁴
Raised liver enzymes NCI lists "high levels of liver enzymes" among reported side effects. No case reports were read.	Not given.	Not stated Not stated.	Authoritative guidance ²⁴

Liver

NCI lists raised liver enzymes among reported side effects of CoQ10. No case reports, LiverTox entry or frequency was read. ²⁴

How often. No frequency was found.

Monitoring. No agency monitoring advice was found.

This is a safety connection. It is not evidence that Coenzyme Q10 supports liver health.

Medicines and supplements 5

With	Why it matters	Importance	Evidence	What to do
Warfarin (blood thinner) prescription	Not established. Older case reports are mentioned in a 2003 trial's introduction as suggesting a weaker warfarin effect; the case reports were not read.	NCCIH and NCI say CoQ10 may change how the body uses warfarin. In a small crossover trial (21 completers, 100 mg a day for 4 weeks) the warfarin dose and INR did not change.	Authoritative guidance and small randomised trial Low certainty ^{23 24 5}	Ask the prescriber or a pharmacist before starting; they may check INR more often.
Insulin and diabetes medicines prescription		NCCIH and NCI say CoQ10 may change how the body uses insulin. A 2018 meta-analysis found small drops in HbA1c and fasting glucose with CoQ10, so blood sugar may need watching.	Authoritative guidance and meta analysis Low certainty ^{23 24 20}	Ask a doctor or pharmacist; blood sugar may need checking.
Cholesterol, blood pressure and blood-sugar medicines prescription		NCI says certain drugs used to lower cholesterol, blood pressure or blood sugar may decrease the effects of CoQ10. Statins lower blood CoQ10 in trials (a 2018 meta-analysis).	Authoritative guidance and meta analysis Low certainty ^{24 16}	Do not stop any of these medicines on your own. Ask the prescriber.
Chemotherapy and radiation prescription	Not established. Concern is that antioxidants might protect cancer cells.	NCCIH says CoQ10 may not be compatible with some cancer treatments. NCI says long-term effects on treatment have not been studied.	Authoritative guidance Not enough evidence ^{23 24}	Tell the oncology team about every supplement.
Other antioxidant supplements and vitamin E supplement	Not studied here.	In the NIH Parkinson trial, CoQ10 and vitamin E were given together. No interaction was reported in the abstract, but none was tested.	No data Not enough evidence ¹²	Ask a pharmacist.

Who should check first 6

Situation	Advice	Evidence
Pregnancy and breastfeeding	No source read gave safety information for pregnancy or breastfeeding. Ask a doctor or pharmacist before use.	No data ^{23 24}
Children	No source read covered supplement use in healthy children. CoQ10 is used for rare inherited deficiency under specialist care (MedlinePlus Genetics).	Authoritative guidance ²²
Cancer treatment	Check with the oncology team before use (see key warnings).	Authoritative guidance ^{24 23}
Warfarin or insulin use	Ask the prescriber or a pharmacist before starting.	Authoritative guidance ^{23 24}
Liver disease	NCI lists raised liver enzymes among reported effects; no specific advice for people with liver disease was read. Ask a doctor.	Authoritative guidance ²⁴
Upcoming surgery	Tell the surgical team about any supplement.	Authoritative guidance ²³

Overdose, product quality and regulators

Summary. Two published safety reviews found CoQ10 has low toxicity and no serious side effects in humans.

Animal. Hidaka 2008 reports a 52-week rat study used to calculate an acceptable daily intake; the abstract does not give more detail.

High dose or long term signals. Hathcock 2006 found stomach and gut complaints were no more common at 1,200 mg than at 60 mg a day. Both reviews put an "observed safe level" at 1,200 mg a day, and say data above that are too thin to judge. These are the authors' estimates, not a regulator's limit and not advice to take any amount.

Overdose response. No overdose information was read.

Genotoxicity. Not researched.

Contamination and label accuracy of CoQ10 products were not researched. NCI says the FDA does not regularly review how supplements are made, so batches and brands may differ.

Quality control. NCI says FDA good manufacturing rules require finished batches to be safe and labels to be true, but supplement manufacture is not regularly reviewed. ²⁴

Body	Action	Date
NCCIH (US National Center for Complementary and Integrative Health) (United States)	Says no serious side effects have been reported; mild side effects such as insomnia or digestive upset may occur; CoQ10 may interact with warfarin and insulin and may not be compatible with some cancer treatments. Says overall evidence does not support CoQ10 for statin muscle pain. source	2019-01
National Cancer Institute (PDQ) (United States)	Says the FDA has not approved CoQ10 as a cancer treatment, lists reported side effects and interactions, and notes limits of the evidence. source

When to get medical help

Rash with swelling of the face or lips, or trouble breathing after taking CoQ10: get emergency help.
Unusual bleeding or bruising, or black stools, if you take warfarin: contact your doctor straight away.
Shaky, sweaty or confused with low blood sugar if you use insulin or diabetes medicines: treat as your doctor has told you and call them.
Yellow skin or eyes, dark urine or severe stomach pain: see a doctor (possible liver problem).
New chest pain, fainting, or sudden worsening of breathlessness or leg swelling in heart failure: call emergency services.

Stop using the product and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.

General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.

Frequently asked questions

What is coenzyme Q10?

Coenzyme Q10 (CoQ10) is a substance your body makes and uses in cells to produce energy. It also acts as an antioxidant. Ubiquinone and ubiquinol are its two chemical forms.

^{24 22}

Do I get CoQ10 from food?

Yes, a few milligrams a day. Meat, fish, nuts and some oils have the most. Typical diets give about 3 to 6 mg a day, mostly from meat and poultry.

^{13 18}

Is CoQ10 good for the heart?

In heart failure, reviews found probably fewer deaths and hospital stays when CoQ10 was added to usual care, but the evidence is mostly from one large trial and Cochrane calls it not convincing. For preventing heart disease, NCCIH says results are inconclusive. It does not replace heart medicines.

^{2 19 23}

Does CoQ10 help with statin muscle pain?

Studies disagree. One meta-analysis found less pain, two found no clear benefit, and NCCIH says the overall evidence does not support it. Do not stop a statin without asking your prescriber.

^{15 9 4 23}

Does CoQ10 lower blood pressure?

A Cochrane review found it probably has no clinically meaningful effect, though the trials were very small.

⁸

Does CoQ10 help with migraine?

Six small trials found fewer and shorter attacks but no change in severity. Some combined CoQ10 with other supplements, so the evidence is low in certainty.

¹⁷

Does CoQ10 help Parkinson disease?

A large trial in early Parkinson disease found no benefit. NCCIH says CoQ10 is not helpful for Parkinson symptoms.

^{12 23}

Is ubiquinol better than ubiquinone?

Studies disagree. A 12-person study found higher blood levels after ubiquinol, but a 21-person crossover found no significant difference. Blood levels are not the same as benefit.

^{10 14}

Is CoQ10 safe?

NCCIH says no serious side effects have been reported and mild ones such as insomnia or stomach upset can occur. NCI also lists raised liver enzymes, headache, dizziness and rash. Published safety reviews found low toxicity.

^{23 24 6 7}

Does CoQ10 interact with medicines?

NCCIH and NCI say it may change how the body uses warfarin and insulin, and it may not be compatible with some cancer treatments. One small trial found no change in warfarin dose. Ask a pharmacist before combining.

^{23 24 5}

Is CoQ10 safe during cancer treatment?

Not known. NCI says long-term effects on treatment were not followed, and an observational study linked antioxidant supplements to worse breast cancer outcomes. Check with the cancer team first.

^{24 23}

Can pregnant or breastfeeding women or children use it?

No source read gave safety data for pregnancy, breastfeeding or healthy children. Ask a doctor or pharmacist.

^{23 24}

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Editorial transparency

Written by: AlternativeMed editorial team. Research compiled with AI assistance, then checked against the sources listed.
Medical review: None. This page has not been reviewed by a physician or pharmacist.
First published: 2026-10-26
Last substantive update: 2026-10-26
How we research: We started from our existing summary, read the NCCIH, NCI and MedlinePlus Genetics pages, and re-read PubMed abstracts for reviews and trials. Only abstracts were read for studies. The NIH Office of Dietary Supplements page was blocked and is marked unread.
How we rate evidence: See "How we rate evidence" in the Evidence tab.
Independence: No product is promoted on this page. No affiliate links are shown. Funding is often not stated in abstracts, so company links to some trials cannot be ruled out.

Sources 25

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

Akhigbe TM, Fidelis FB, Adekunle AO, Ashonibare VJ, Akorede BA, Shuaibu MS et al. Does coenzyme Q10 improve semen quality and circulating testosterone level? a systematic review and meta-analysis of randomized controlled trials.. Front Pharmacol. 2024. PMID 39830337. DOI 10.3389/fphar.2024.1497930. (abstract)
Al Saadi T, Assaf Y, Farwati M, Turkmani K, Al-Mouakeh A, Shebli B et al. Coenzyme Q10 for heart failure.. Cochrane Database Syst Rev. 2021. PMID 35608922. DOI 10.1002/14651858.CD008684.pub3. (abstract)
Bakri S, Saleh R, Cayan S, Birowo P, Atmoko W, Zainal ATF et al. Efficacy and Safety of Coenzyme Q10 in Idiopathic Male Infertility: A Systematic Review and Meta-Analysis of Randomized Trials.. World J Mens Health. 2026. PMID 40878114. DOI 10.5534/wjmh.250159. (abstract)
Banach M, Serban C, Sahebkar A, Ursoniu S, Rysz J, Muntner P et al. Effects of coenzyme Q10 on statin-induced myopathy: a meta-analysis of randomized controlled trials.. Mayo Clin Proc. 2015. PMID 25440725. DOI 10.1016/j.mayocp.2014.08.021. (abstract)
Engelsen J, Nielsen JD, Hansen KF. Effect of Coenzyme Q10 and Ginkgo biloba on warfarin dosage in patients on long-term warfarin treatment. A randomized, double-blind, placebo-controlled cross-over trial.. Ugeskr Laeger. 2003. PMID 12772396. (abstract)
Hathcock JN, Shao A. Risk assessment for coenzyme Q10 (Ubiquinone).. Regul Toxicol Pharmacol. 2006. PMID 16814438. DOI 10.1016/j.yrtph.2006.05.006. (abstract)
Hidaka T, Fujii K, Funahashi I, Fukutomi N, Hosoe K. Safety assessment of coenzyme Q10 (CoQ10).. BioFactors. 2008. PMID 19096117. DOI 10.1002/biof.5520320124. (abstract)
Ho MJ, Li EC, Wright JM. Blood pressure lowering efficacy of coenzyme Q10 for primary hypertension.. Cochrane Database Syst Rev. 2016. PMID 26935713. DOI 10.1002/14651858.CD007435.pub3. (abstract)
Kennedy C, Köller Y, Surkova E. Effect of Coenzyme Q10 on statin-associated myalgia and adherence to statin therapy: A systematic review and meta-analysis.. Atherosclerosis. 2020. PMID 32179207. DOI 10.1016/j.atherosclerosis.2020.03.006. (abstract)
Langsjoen PH, Langsjoen AM. Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone.. Clin Pharmacol Drug Dev. 2014. PMID 27128225. DOI 10.1002/cpdd.73. (abstract)
Mortensen SA, Rosenfeldt F, Kumar A, Dolliner P, Filipiak KJ, Pella D et al. The effect of coenzyme Q10 on morbidity and mortality in chronic heart failure: results from Q-SYMBIO: a randomized double-blind trial.. JACC Heart Fail. 2014. PMID 25282031. DOI 10.1016/j.jchf.2014.06.008. (abstract)
Parkinson Study Group QE3 Investigators, Beal MF, Oakes D, Shoulson I, Henchcliffe C, Galpern WR et al. A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit.. JAMA Neurol. 2014. PMID 24664227. DOI 10.1001/jamaneurol.2014.131. (abstract)
Pravst I, Zmitek K, Zmitek J. Coenzyme Q10 contents in foods and fortification strategies.. Crit Rev Food Sci Nutr. 2010. PMID 20301015. DOI 10.1080/10408390902773037. (abstract)
Pravst I, Rodríguez Aguilera JC, Cortes Rodriguez AB, Jazbar J, Locatelli I, Hristov H et al. Comparative Bioavailability of Different Coenzyme Q10 Formulations in Healthy Elderly Individuals.. Nutrients. 2020. PMID 32188111. DOI 10.3390/nu12030784. (abstract)
Qu H, Guo M, Chai H, Wang WT, Gao ZY, Shi DZ. Effects of Coenzyme Q10 on Statin-Induced Myopathy: An Updated Meta-Analysis of Randomized Controlled Trials.. J Am Heart Assoc. 2018. PMID 30371340. DOI 10.1161/JAHA.118.009835. (abstract)
Qu H, Meng YY, Chai H, Liang F, Zhang JY, Gao ZY et al. The effect of statin treatment on circulating coenzyme Q10 concentrations: an updated meta-analysis of randomized controlled trials.. Eur J Med Res. 2018. PMID 30414615. DOI 10.1186/s40001-018-0353-6. (abstract)
Sazali S, Badrin S, Norhayati MN, Idris NS. Coenzyme Q10 supplementation for prophylaxis in adult patients with migraine-a meta-analysis.. BMJ Open. 2021. PMID 33402403. DOI 10.1136/bmjopen-2020-039358. (abstract)
Weber C, Bysted A, Hølmer G. The coenzyme Q10 content of the average Danish diet.. Int J Vitam Nutr Res. 1997. PMID 9129255. (abstract)
Xu J, Xiang L, Yin X, Song H, Chen C, Yang B et al. Efficacy and safety of coenzyme Q10 in heart failure: a meta-analysis of randomized controlled trials.. BMC Cardiovasc Disord. 2024. PMID 39462324. DOI 10.1186/s12872-024-04232-z. (abstract)
Zhang SY, Yang KL, Zeng LT, Wu XH, Huang HY. Effectiveness of Coenzyme Q10 Supplementation for Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis.. Int J Endocrinol. 2018. PMID 30305810. DOI 10.1155/2018/6484839. (abstract)
de Frutos F, Gea A, Hernandez-Estefania R, Rabago G. Prophylactic treatment with coenzyme Q10 in patients undergoing cardiac surgery: could an antioxidant reduce complications? A systematic review and meta-analysis.. Interact Cardiovasc Thorac Surg. 2015. PMID 25344142. DOI 10.1093/icvts/ivu334. (abstract)
. MedlinePlus Genetics: Primary coenzyme Q10 deficiency. . . (full-text)
. NCCIH: Coenzyme Q10 (Last Updated January 2019). . . (full-text)
. National Cancer Institute: Coenzyme Q10 (PDQ), Patient Version. . . (full-text)
. NIH Office of Dietary Supplements: Coenzyme Q10 fact sheet. . . (not-read)

Where to buy

Check the label first. Whatever you buy, look for these:

The amount of the active ingredient per serving, not just the front-label claim
A third-party testing mark (USP, NSF or ConsumerLab)
Other ingredients and allergens
Ask a pharmacist about interactions with your medicines

Talk to a pharmacist or doctor before you start any supplement, especially if you take medicines. See the Safety tab for interactions.

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