For Patients & Caregivers
Bottom Line: Coenzyme Q10 has not been shown to treat or prevent cancer.
Coenzyme Q10 (CoQ10) is produced naturally by all cells in the body. It is necessary for production of adenosine triphosphate (ATP), the “fuel” of all living cells. During periods of ischemia (lack of oxygen), such as occurs during a heart attack, CoQ10 has been shown to reduce damage to heart tissue and its mitochondria (where ATP production takes place). It is known to be an antioxidant and to stabilize cell and organelle membranes. In animal studies, coenzyme Q10 is able to neutralize free radicals, which can damage DNA and cells. However, absorption of oral coenzyme Q10 through the intestine is low. Due to its antioxidant activity, CoQ10 may interfere with the actions of certain chemotherapy drugs and radiation therapy.
- As an antioxidant
Laboratory studies show that CoQ10 has antioxidant effects.
- To treat breast cancer
A few case reports describe remission of breast cancer when treated with high doses of CoQ10, but this is insufficient evidence to support this use.
- To manage cardiovascular disease
Several studies show CoQ10 improves left ventricular function and reduce hypertension. Other studies yielded negative results.
- To reduce high cholesterol
Clinical trials show inconsistent results: two indicate an increase in HDL, one shows a decrease in LDL, while two others indicate that coenzyme Q10 has no effect on LDL oxidation (which contributes to the development of atheroclerotic plaques in the blood vessels).
- To prevent cardiac toxicity from anthracyclines
One clinical trial supports this use, but additional studies are needed.
- To improve athletic performance
Clinical trials do not support this use.
- To prevent the progression of Parkinson’s disease
One clinical trial showed that high doses of coenzyme Q10 slowed the progression of Parkinson’s disease, but larger clinical trials are needed to support this use.
- To treat Huntington’s disease
Data from a single clinical trial do not support this use.
- To treat periodontal disease (disease of the gum, teeth, and underlying bone)
One study supports this use, but additional clinical trials are needed.
Because semen concentrations of coenzyme Q10 and ubiquinol are reduced in infertile men, this randomized, placebo-controlled, double-blind study of 60 infertile men sought to determine if coenzyme Q10 supplementation (200 mg/day) for 6 months could influence fertility. Compared to placebo, coenzyme Q10 improved sperm motility; however, whether coenzyme Q10 can enhance overall fertility has yet to be determined.
- You are taking Warfarin (CoQ10 may lessen its effects).
- You are undergoing chemotherapy (Theoretically, because it is an antioxidant, CoQ10 may decrease the effectiveness of chemotherapy; patients should consult with their oncologist).
- You are taking Theophylline (CoQ delays the clearance of theophylline, which may cause persistent vomiting, cardiac arrhythmias, and intractable seizures).
For Healthcare Professionals
Coenzyme Q10 (CoQ10), also known as ubiquinone, is involved in cellular respiration and energy production. It is found in all human cells, with higher concentrations in the liver, kidney, heart, and pancreas. It is also consumed as a dietary supplement for its antioxidant effects and is often promoted as a preventive agent for cardiovascular diseases, Parkinson’s disease, infertility and cancer.
Studies done in mice indicate antioxidant and neuroprotective effects (17)(18).
Data from clinical trials suggest beneficial effects of CoQ10 in patients with coronary artery disease (2) and congestive heart failure (21).
CoQ10 supplementation may increase sperm motility in asthenozoospermic men (8) and reduce fatigue induced by physical exertion (9).
Putative neuroprotective effects of CoQ10 were reported in patients with progressive supranuclear palsy (5) as well as those with early Parkinson’s disease (6)(33), but not with midstage Parkinson’s disease (7). A mixture of antioxidants, including CoQ10, vitamins C, E, and lipoic acid was found ineffective against Alzheimer’s disease (20).
There may be a role for CoQ10 in the prevention of migraine (22). A small study showed a reduction in the frequency of migraine headaches with CoQ10 supplementation (23), but a randomized trial failed to find benefit (24). More research is warranted.
The observation that patients who receive statin therapy have decreased concentrations of CoQ10 in muscle cells (25) resulted recently in studies to evaluate the benefit of CoQ10 in alleviating statin-induced myalgias. The data are inconclusive (26)(27)(28).
CoQ10 has also been investigated for anticancer effects. A few case reports suggest that CoQ10 supplementation may be useful in the treatment of breast cancer (3)(4). However, a randomized trial did not find any effectiveness in improving self-reported fatigue or quality of life in breast cancer patients (29). Further study is needed.
CoQ10 is structurally similar to vitamin K and can antagonize the effects of warfarin (11)(12).
And because of its antioxidant property, CoQ10 may also reduce effectiveness of chemotherapy and radiation therapy (13).
CoQ10 is known to have antioxidant and membrane stabilizing properties and is the only endogenously produced lipid with a redox function in mammals. All cells are capable of synthesizing CoQ10 and no redistribution between organs occurs through the blood. CoQ10 is necessary for adenosine triphosphate (ATP) production. Its role as a mobile electron carrier in the mitochondrial electron-transfer processes of respiration and coupled phosphorylation is well established. It has a direct regulatory role on succinyl and NADH dehydrogenases (1). CoQ10 has been demonstrated to scavenge free radicals produced by lipid peroxidation and prevent mitochondrial deformity during episodes of ischemia, and it may have some ability to maintain the integrity of myocardial calcium ion channels during ischemic insults (2).
CoQ10 may also be capable of stabilizing cellular membranes and preventing depletion of metabolites required for ATP resynthesis (10), and suppressing age-related inflammatory reactions and osteoclast differentiation by inhibiting oxidative stress (30).
CoQ10 was shown to prevent the reduction of glucose transporter-4 (GLUT4) protein levels in adipocytes caused by simvastatin, which may be one of the mechanisms underlying statin-induced diabetes (31).
In a study of rats, CoQ10 protected against doxorubicin-induced testicular toxicity by ameliorating oxidative stress, reducing apoptosis and by up-regulating testicular P-glycoprotein (32).
HMG-CoA reductase inhibitors: Endogenous levels of CoQ may be reduced by lovastatin, atorvastatin and simvastatin. The HMG-CoA reductase enzyme is responsible for catalyzing the conversion of acetyl CoA to cholesterol and synthesis of CoQ10 (14).
Warfarin: CoQ may antagonize the effects of warfarin. CoQ is structurally similar to vitamin K (11).
Theophylline: CoQ delays the clearance of theophylline, which can cause persistent vomiting, cardiac arrhythmias, and intractable seizures (19).
Balercia G, Buldreghini E, Vignini A, et al. Coenzyme Q(10) treatment in infertile men with idiopathic asthenozoospermia: a placebo-controlled, double-blind randomized trial Fertil Steril. 2009 May;91(5):1785-92.
Because semen concentrations of coenzyme Q10 and ubiquinol are reduced in infertile men, this randomized, placebo-controlled, double-blind study of 60 infertile participants sought to determine if coenzyme Q10 supplementation (200 mg/day) for 6 months could influence fertility. Compared to placebo, coenzyme Q10 increased sperm motility, an effect that was reversed after a 3-month washout period. Participants with the lowest baseline coenzyme Q10 and ubiquinol concentrations as well as sperm motility were most likely to receive benefits of coenzyme Q10 supplementation. The authors propose that coenzyme Q10’s antioxidant properties may be responsible for the increase in sperm motility; however, whether coenzyme Q10 enhances overall fertility has yet to be determined.