Coenzyme Q10

A reference work, not a recommendation to use: this profile describes mechanism and evidence and does not replace medical advice. The claims come from marketing and forums and are tested here, not endorsed.

Claims checked

• More energy and less fatigue

  Small benefit

  Energy & metabolism · mixed: healthy people and patients · Human, randomised

  Meta-analysis of 13 RCTs with 1126 participants: small reduction in fatigue (g −0.40), in the same direction in healthy and ill people ^[14]; in a meta-analysis in healthy people, the effect on subjective fatigue was only tentatively documented ^[13].

• Better athletic performance

  Mixed results

  Muscle & performance · healthy · Human, randomised

  Meta-analysis of 24 studies: blood levels rise reliably, performance effects small, inconsistent and not stable after exclusion of outliers; certainty very low to low ^[13].

• Relieves muscle complaints on statins

  Mixed results

  Muscle & performance · Patients: statin therapy with muscle complaints · Human, randomised

  Two meta-analyses found no benefit ^[7][9], two a relief of complaints ^[8][10]; creatine kinase remained unchanged ^[7][8].^{[7][8][9][10]}

• Strengthens the heart in heart failure

  Single unconfirmed finding

  Heart & blood vessels · Patients: chronic heart failure · Human, randomised

  Fewer major cardiovascular events and deaths in an RCT with 420 affected people ^[11]; according to the Cochrane review, the mortality benefit rests on this one study, and overall convincing evidence is lacking ^[12].

Mechanism of action

Coenzyme Q10 is a fat-soluble quinone that passes electrons along the respiratory chain in the inner mitochondrial membrane and transports protons across the membrane in the process. In its reduced form (ubiquinol), it acts as an antioxidant in all membranes, directly or by regenerating tocopherol and ascorbate. A deficiency can arise from mutations in biosynthesis genes or from inhibition of biosynthesis by HMG-CoA reductase inhibitors (statins) ^[1]. A meta-analysis of placebo-controlled studies confirms that statins lower the CoQ10 concentration in plasma (on average −0.44 µmol/L), regardless of the type of statin ^[2].

Absorption from the gut is slow and depends strongly on the formulation; a review by two employees of a CoQ10 manufacturer stresses the importance of a dissolved rather than crystalline form of the active ingredient and does not regard ubiquinol as the more active form because both forms are constantly interconverted in the body ^[3]. In a crossover study with 14 young healthy people, seven preparations differed markedly; soft gel capsules with ubiquinone or ubiquinol were absorbed best, and differences between individuals were large ^[4]. In ten older men, ubiquinol over two weeks significantly raised total CoQ10 in plasma (1.5-fold), ubiquinone did not do so significantly; CoQ10 and ATP in blood cells and markers of oxidative stress remained unchanged ^[5]. In a single-dose study with 21 healthy older adults, ubiquinol was not significantly better than ubiquinone (1.7-fold), whereas a water-soluble formulation was 2.4-fold; in blood, CoQ10 was present predominantly as ubiquinol regardless of the form taken ^[6].

For statin-associated muscle complaints, meta-analyses contradict each other: one found no effect on muscle pain and creatine kinase in 302 treated people ^[7], another with 12 RCTs and 575 treated people found less pain, weakness, cramps and fatigue with unchanged creatine kinase ^[8]. A meta-analysis in people with statin-associated myalgia found neither less pain nor better adherence ^[9], the most recent, with seven RCTs, a small pain relief ^[10]. In chronic heart failure, CoQ10 reduced major cardiovascular events after two years in the Q-SYMBIO RCT with 420 affected people (15% vs. 26%), while the short-term endpoints after 16 weeks did not change ^[11]. A Cochrane review rates the mortality benefit as likely but bases it on this one study and sees overall no convincing evidence for or against use ^[12]. In healthy people, blood levels rise reliably, but performance effects are small and inconsistent ^[13]; a meta-analysis of 13 RCTs found a small reduction in fatigue (Hedges g −0.40) ^[14]. In an RCT with 24 people on long-term warfarin treatment, CoQ10 changed neither INR nor warfarin requirement ^[15].

Information on forms: ubiquinone and ubiquinol have their own form profiles (ubichinon, ubichinol). The meta-analyses on statin complaints, performance and fatigue ^{[7][8][9][10][13][14]} and the Cochrane review ^[12] do not separate by redox form in the abstract; Q-SYMBIO ^[11] used ubiquinone according to an analysis of the European centers (evidence in the form profile ubichinon). According to the form rule, studies without information on the form do not count toward the rating in the form profiles; in this overview profile, they stand for coenzyme Q10 as a whole.

Assigned to the site of action Cell with mitochondrion, glutathione cycle, Keap1–Nrf2 and plasma membrane; not drawn in its figure: same finding as ubiquinol, which is drawn.

Targets

Effect profile

Which signaling systems the compound affects according to current data. ↑ enhanced, ↓ dampened, ≈ modulated, ○ no effect; dots = evidence level.

• ·Dopamineno data
• ·Noradrenalineno data
• ·Serotoninno data
• ·Acetylcholineno data
• ·Glutamate · AMPAno data
• ·Glutamate · NMDAno data
• ·GABAno data
• ·Histamineno data
• ·Orexinno data
• ·Adenosineno data
• ·Opioidsno data
• ·Melatoninno data
• ·Neurotrophinsno data
• ·Blood flowno data
• ·Nitric oxideno data
• ?Energy metabolismunclear · central electron carrier of the respiratory chain; supplementation raises blood levels, but in a small RCT not CoQ10 and ATP in blood cells^[1][5][13]
• ·Insulin · glucoseno data
• ○Inflammation · oxidativeno effect · markers of oxidative stress unchanged in a small RCT in older men^[5]
• ·Stress axisno data
• ·Testosterone axisno data
• ·Endocannabinoidsno data
• ·Autophagy · senescenceno data
• ·Immune systemno data
• ·Lipid metabolismno data
• ·Coagulation · fibrinolysisno data
• ·Methylationno data

Routes of administration and bioavailability

How much of a compound reaches the blood or target tissue depends on the route into the body and on the dosage form. All routes of administration explained

• Oral (swallowed) · Ubiquinone (soft gel capsule, dissolved in oil)

  absolute bioavailability not determined; strongly dependent on formulation and individual

  Soft gel capsules with dissolved ubiquinone were among the best-absorbed preparations in a crossover study ^[4]. In blood, CoQ10 is present predominantly as ubiquinol, even when ubiquinone was taken ^[6].

  Human, randomised

• Oral (swallowed) · Ubiquinol (reduced form)

  compared with ubiquinone 1.5-fold (significant, 10 men) or 1.7-fold (not significant, 21 older adults)

  Better than ubiquinone in older men over two weeks ^[5], not significant in a single-dose study in older adults ^[6]; a review close to the manufacturer regards the assumption of a more active form as unfounded ^[3].

  Human, randomised

• Oral (swallowed) · water-soluble, solubilized

  2.4-fold vs. ubiquinone capsule (single dose, 21 older adults)

  Absorbed better than ubiquinone capsules in one study ^[6]; the composition of the formulation generally strongly influences absorption ^[4].

  Human, randomised

Human studies

• Seven preparations compared

  crossover study, double-blind, single doses · healthy (young) · n = 14 · single doses, 48 h measurement each

  Measured: Area under the plasma curve

  Result: Large differences; soft gel capsules with ubiquinone or ubiquinol best; marked individual differences.^[4]

  Human, randomised

• Ubiquinol vs. ubiquinone in older men

  RCT, double-blind, crossover · healthy (older men) · n = 10 · 2 × 2 weeks

  Measured: CoQ10 in plasma and blood cells, oxidative stress, ATP

  Result: Ubiquinol: total CoQ10 1.5-fold (significant), ubiquinone not significant; blood cells, ATP and stress markers unchanged.^[5]

  Human, randomised

• Three formulations in older adults

  randomized crossover study, single dose · healthy (65 to 74 years) · n = 21 · single doses, 48 h measurement

  Measured: Area under the plasma curve

  Result: Water-soluble 2.4-fold, ubiquinol 1.7-fold (not significant) vs. ubiquinone.^[6]

  Human, randomised

• Meta-analysis statin-associated muscle complaints (positive)

  meta-analysis of 12 RCTs · Patients: statin therapy · n = 575

  Measured: Muscle pain, weakness, cramps, fatigue, creatine kinase

  Result: Complaints relieved, creatine kinase unchanged.^[8]

  Human, randomised

• Meta-analysis statin-associated myalgia (negative)

  meta-analysis of 7 RCTs · Patients: statin-associated myalgia · n = 321

  Measured: Muscle pain, adherence

  Result: No difference from placebo (WMD −0.42; 95% CI −1.47 to 0.62).^[9]

  Human, randomised

• Q-SYMBIO

  RCT, double-blind, multicenter · Patients: moderate to severe heart failure · n = 420 · 2 years

  Measured: major cardiovascular events; short-term endpoints after 16 weeks

  Result: 15% vs. 26% events (HR 0.50); short-term endpoints unchanged.^[11]

  Human, randomised

• Meta-analysis fatigue

  meta-analysis of 13 RCTs · healthy and patients · n = 1126

  Measured: Fatigue scores

  Result: Hedges g −0.40 (95% CI −0.64 to −0.16).^[14]

  Human, randomised

• Warfarin interaction

  RCT, double-blind, placebo-controlled, crossover · Patients: long-term warfarin therapy · n = 24 · 4 weeks each

  Measured: INR, warfarin requirement

  Result: INR stable, warfarin requirement unchanged.^[15]

  Human, randomised

Risks and warnings

• Tolerability

  In a meta-analysis, only one adverse event (gastrointestinal) was reported with CoQ10 in 602 people ^[14]; according to the Cochrane review, the evidence on adverse effects in heart failure is of low quality and not clear-cut ^[12].

  Human, randomised

• Interaction with warfarin

  Case reports describe a weaker response to warfarin; in a small RCT, INR and warfarin requirement remained unchanged ^[15]. Larger studies are lacking.

  Human, randomised

• Product quality and formulation

  Absorption differs markedly between preparations ^[4][6]. Several papers on bioavailability come from employees of a manufacturer ^[3].

  Human, randomised

Interactions

• Warfarin: In an RCT with 24 participants, no influence on INR and warfarin requirement; case reports had described a weaker response ^[15].
• Statins: Statins lower the CoQ10 concentration in plasma because they inhibit its biosynthesis ^[1][2].

Fact check: common claims

• partly supported

  “Ubiquinol is the better, active form of Q10”

  In one small RCT, plasma levels rose more with ubiquinol ^[5], not significantly in another study ^[6]; in blood, CoQ10 is predominantly present as ubiquinol anyway ^[6], and the formulation has a greater effect than the redox form ^[4]. Whether ubiquinol works better clinically has not been studied.

• partly supported

  “Anyone taking statins needs Q10 against muscle pain”

  Statins lower CoQ10 in plasma ^[2], but meta-analyses on the effect on muscle complaints contradict each other ^{[7][8][9][10]}.

• not supported

  “Q10 increases the energy of the mitochondria and thus performance in healthy people”

  CoQ10 and ATP in blood cells remained unchanged in one RCT ^[5]; performance effects in healthy people are small and unstable ^[13].

• partly supported

  “Q10 lowers mortality in heart failure”

  Shown in one RCT ^[11]; according to the Cochrane review, confirmation by further studies is lacking ^[12].

• not supported

  “Q10 cancels the effect of anticoagulants”

  Case reports only; in an RCT, no change in INR and warfarin requirement ^[15].

Pharmacokinetics

Absorption

Oral, slow and strongly formulation-dependent, with large differences between individuals ^[3][4].

Half-life

Not verified.

Metabolism

Ubiquinone and ubiquinol are interconverted in the body; in blood predominantly as ubiquinol ^[3][6].

Entry into the brain

Not verified.

Legal status

Germany

Not verified.

EU

No entry “coenzyme Q10”, “ubiquinone” or “ubiquinol” in the consolidated Union list of novel foods, as of August 10, 2026 ^[16]; no EU legal act with “coenzyme Q10” or “ubiquinol” in the title and no EFSA novel food opinion found in PubMed. According to the Novel Food Catalogue, coenzyme Q10 is considered not novel in foods (entry POL-NF-00261 “Coenzyme Q10”, last modified May 8, 2023); the entry names no form (ubiquinone or ubiquinol) ^[17]. The catalogue is a guidance tool of the Commission, not a legal act.

USA

Not verified.

Other countries

Not verified.

Related compounds

Open questions

• Does supplementation also raise CoQ10 meaningfully in muscle, heart or mitochondria of healthy people?
• Which formulation is best absorbed for the same redox form, independent of manufacturer claims?
• Can the Q-SYMBIO finding in heart failure be confirmed in a second large RCT?
• Which subgroup with statin-associated muscle complaints benefits, if any?