Supplement Forms/Alternate Names:
Principal Proposed Uses
• Congestive Heart Failure; Cardiomyopathy; Heart Attack Recovery; Hypertension; Nutrient Depletion/Interference Caused by Various Medications
Other Proposed Uses
• Amyotrophic Lateral Sclerosis (Lou Gehrig's Disease); Asthma; Diabetes; Kidney Failure; Migraine Headaches; Parkinson's Disease; Periodontal Disease; Preeclampsia and Pregnancy-induced Hypertension; Sports Performance Enhancement; Tinnitus
Coenzyme Q 10 (CoQ 10), also known as ubiquinone, is a major part of the body's mechanism for producing energy. The name of this supplement comes from the word ubiquitous, which means "found everywhere." Indeed, CoQ 10 is found in every cell in the body. It plays a fundamental role in the mitochondria, the parts of the cell that produce energy from glucose and fatty acids.
Japanese scientists first reported therapeutic properties of CoQ 10 in the 1960s. Some evidence suggests that CoQ 10 might assist the heart during times of stress on the heart muscle, perhaps by helping it use energy more efficiently.
CoQ 10's best-established use is for congestive heart failure, but the evidence that it works is not entirely consistent. Ongoing research suggests that it may also be useful for other types of heart problems, Parkinson's disease, and several additional illnesses. It is generally used in addition to, rather than instead of, standard therapies.
CoQ 10 supplementation might also be of value for counteracting side effects of certain prescription medications.
Every cell in your body needs CoQ 10, but there is no dietary requirement as the body can manufacture CoQ 10 from scratch.
The typical recommended dosage of CoQ 10 is 30 mg to 300 mg daily; higher daily intakes have been used in some studies.
CoQ 10 is fat soluble and may be better absorbed when taken in an oil-based soft gel form rather than in a dry form such as tablets and capsules.1,81 Dividing the total daily dosage up into two or more separate doses may produce higher blood levels.81
A finely ground up (“nanoparticular”) form of the supplement appears to be much better absorbed than standard CoQ 10 products.86
Although not all studies have been positive, some evidence supports the use of CoQ 10 for treating congestive heart failure.33-36,51-52,66,83 Keep in mind that CoQ 10 is taken along with conventional medications, not as a replacement for them.
Weaker evidence suggests that this supplement may be useful for heart attack recovery,63,64,67,68 cardiomyopathy,5-7 hypertension,8-11,58 diabetes,40,58 strengthening the heart prior to heart surgery,69 and migraine headaches.75 Although CoQ 10 has been widely advertised as effective for treating and Parkinson's disease, in fact, there is only minimal evidence that it works, and some evidence that it does not work.57,65,86
CoQ 10 has shown the potential to prevent heart damage and other side effects caused by certain types of cancer chemotherapy.59-61 This evidence is weak, however, and as yet it cannot be stated with any certainty that CoQ 10 is actually helpful.70
CoQ 10 has shown some preliminary promise as an aid to the treatment of kidney failure.49
Note: People with severe illnesses, such as heart disease, cancer, or kidney failure, should not use CoQ 10, or any supplement, except under physician supervision.
Certain medications may interfere with the body's production of CoQ 10, or partially block its function. The best evidence regards cholesterol-lowering drugs in the statin family, such as lovastatin (Mevacor), simvastatin (Zocor), and pravastatin (Pravachol), along with the supplement red yeast rice (which contains naturally occurring statins). These medications impair CoQ 10 synthesis as an inevitable side effect of their mechanism of action.22-25,89 Since these drugs are used to protect the heart, and since CoQ 10 deficiency could in theory impair heart function, it has been suggested that this side effect may work against the intended purpose of taking statins. Furthermore, one might naturally guess that some of the side effects of statins could be caused by this induced CoQ 10 deficiency. However, studies designed to determine whether the use of CoQ 10 supplements actually offers any benefit to people taking statins have returned inconsistent results at best.76,77,87,88,90,91
For several other categories of drugs, the evidence that they interfere with CoQ 10 is provocative but even less reliable. These include oral diabetes drugs (especially glyburide, phenformin, and tolazamide), beta-blockers (specifically propranolol, metoprolol, and alprenolol), antipsychotic drugs in the phenothiazine family, tricyclic antidepressants, methyldopa, hydrochlorothiazide, clonidine, and hydralazine.26-31 Again, while in theory CoQ 10 supplementation might be helpful for people using these medications, there is no direct evidence to support this hypothesis.
CoQ 10 has also been suggested as a performance enhancer for athletes. However, while one double-blind study of 25 highly trained cross-country skiers found some benefit,15 most studies evaluating potential sports supplement uses of CoQ 10 have returned negative rather than positive results.16-21, 78
CoQ 10 is also sometimes claimed to be an effective treatment for periodontal disease. However, the studies on which this idea is based are too flawed to be taken as meaningful.12 Even weaker evidence, far too weak to rely upon at all, hints that CoQ 10 might be useful in some cases of tinnitus (ringing in the ear).
One preliminary study of CoQ 10 for people undergoing treatment for HIV found conflicting results; the supplement appeared to improve general well-being, but it did not protect mitochondria (as the researchers had hoped it would) and actually seemed to worsen symptoms of nerve-related pain (peripheral neuropathy).71
Preliminary evidence, far too weak to be relied upon at all, has been used to suggest that coenzyme Q10 might be helpful for asthma,82 as well as reducing the side effects (specifically, cardiac toxicity) of the cancer chemotherapy drug doxorubicin.84
CoQ 10 has additionally been proposed as a treatment for a wide variety of other conditions, including angina, cancer, male infertility, muscular dystrophy, and obesity, but there is, as yet, no evidence that it is effective.
What Is the Scientific Evidence for Coenzyme Q 10 ?
Congestive Heart Failure
Most but not all studies tell us that CoQ 10 can be helpful for people with congestive heart failure (CHF). In this serious condition, the heart muscles become weakened, resulting in poor circulation and shortness of breath.
People with CHF have significantly lower levels of CoQ 10 in heart muscle cells than do healthy people.32 This fact alone does not prove that the supplements will help CHF; however, it prompted medical researchers to try using CoQ 10 as a treatment for heart failure.
A large systematic review of 7 randomized trials found some benefits with coenzyme Q supplements.95 The randomized trials evaluated CoQ 10 supplements in 914 patients with chronic heart failure. When compared to placebo, CoQ 10 was associated with an improvement in the severity of heart failure symptoms in 2 of 3 trials. In one trial of 614 patients, 2 mg per kilogram body weight of CoQ 10 reduced re-hospitalization, acute pulmonary edema, cardiac asthma, and arrhythmia when compared to placebo.33 Although, a second trial of 87 patients showed no significant differences in mortality.
Similarly positive results were also seen in other double-blind studies involving a total of more than 270 participants.34-35,53,83 One double-blind study found that in people with heart failure so severe they were waiting for a heart transplant, use of CoQ 10 improved subjective symptoms.72
However, two very well-designed double-blind studies published in 1999 and 2000 enrolling a total of about 85 people with congestive heart failure failed to find any evidence of benefit.36,54 The reason for this discrepancy is not clear.
Cardiomyopathy is the general name given to conditions in which the heart muscle gradually becomes diseased. Several small studies suggest that CoQ 10 supplements are helpful for some forms of cardiomyopathy.37-39
An 8-week, double-blind, placebo-controlled study of 59 men already taking medications for high blood pressure found that 120 mg daily of CoQ 10 reduced blood pressure by about 9% as compared to placebo.40
A 12-week, double-blind, placebo-controlled study of 83 people with isolated systolic hypertension (a type of high blood pressure in which only the "top" number is high) found that use of CoQ 10 at a dose of 60 mg daily improved blood pressure measurements to a similar extent.50
Similarly, in a 12-week, double-blind, placebo-controlled trial of 74 people with diabetes, use of CoQ 10 at a dose of 100 mg twice daily significantly reduced blood pressure as compared to placebo.58
Antihypertensive effects were also seen in previous smaller trials, most of which were not double-blind.41-43
CoQ 10 may also be beneficial in reducing the risk of high blood pressure during pregnancy ( pre-eclampsia).92 Two hundred and thirty-five pregnant women at risk for pre-eclampsia were randomized to receive CoQ 10 (200 mg daily) or placebo for 20 weeks until they delivered their babies. The women in the treatment group had fewer cases of pre-eclampsia compared to those who took the placebo.
Heart Attack Recovery
In a double-blind trial, 144 people who had recently experienced a heart attack were given either placebo or 120 mg of CoQ 10 daily for 1 year, along with conventional treatment.63,73 The results showed that participants receiving CoQ 10 experienced significantly fewer heart-related problems, such as episodes of angina pectoris or arrhythmia, or recurrent heart attacks.
A double-blind study of 49 people who had suffered a full cardiac arrest requiring cardiopulmonary resuscitation (CPR) found that use of CoQ 10 along with mild hypothermia (chilling of the body) was more effective than mild hypothermia plus placebo.74
Note: Individuals recovering from a heart attack should not take any herbs or supplements except under the supervision of a physician.
A study published in 2002 raised hopes that CoQ 10 might help slow the progression of Parkinson’s disease. In this 16-month, double-blind, placebo-controlled trial, 80 people with Parkinson’s disease were given either CoQ 10 (at a dose of 300 mg, 600 mg, or 1,200 mg daily) or placebo.57 Participants in this trial had early stages of the disease and did not yet need medication. The results appeared to suggest that CoQ 10, especially at the highest dose, might have slowed disease progression. However, for a variety of statistical reasons, the results were in fact quite inconclusive.
A subsequent double-blind, placebo-controlled study of 28 people with Parkinson’s disease, which was well-controlled by medications, indicated that 360 mg of CoQ 10 daily could produce a mild improvement in some symptoms.65 Based on these results, a more substantial study was undertaken, enrolling 131 people with Parkinson’s disease (again, well-controlled by medications).86 This repeat trial used a specially finely ground up form of CoQ 10 that, though taken at a dose of only 300 mg daily, produced blood levels of the supplement equivalent to those produced by 1,200 mg daily of ordinary CoQ 10. Unfortunately, it didn’t work. While benefits were seen in both the placebo and the CoQ 10 group, CoQ 10 failed to prove more effective than placebo.
Further trials will be necessary to confirm (or deny) these results.
In the 12-week, double-blind, placebo-controlled trial of 74 people with diabetes mentioned above, use of CoQ 10 at a dose of 100 mg twice daily significantly improved blood sugar control as compared to placebo.58 Similar benefits were seen in the 8-week, double-blind, placebo-controlled study of 59 men also described above.40 However, a third study failed to find any effect on blood sugar control.62
In general, CoQ 10 appears to be extremely safe. No significant side effects have been found, even in studies that lasted a year.44,79 However, people with severe heart disease should not take CoQ 10 (or any other supplement) except under a doctor's supervision.
As noted above, two studies suggest that CoQ 10 might reduce blood sugar levels in people with diabetes.45 While this could potentially be helpful for treatment of diabetes, it might present a risk as well; people with diabetes who are using CoQ 10 might inadvertently push their blood sugar levels dangerously low. However, another trial in people with diabetes found no effect on blood sugar control.46,58 The bottom line: If you have diabetes, make sure to track your blood sugar closely if you start taking CoQ 10 (or, indeed, any herb or supplement).
CoQ 10 chemically resembles vitamin K. Since vitamin K counters the anticoagulant effects of warfarin (Coumadin), it has been suggested that CoQ 10 may have the same effect.47,55 However, a small, double-blind study found no interaction between CoQ 10 and warfarin.56 Nonetheless, in view of warfarin’s low margin of safety, prudence indicates physician supervision before combining CoQ 10 with warfarin.
CoQ 10 might also interact with reverse transcriptase inhibitors used for treatment of HIV (for example, lamivudine and zidovudine). These medications can cause damage to the mitochondria, the energy-producing subunits of cells, leading in turn to a variety of side effects, including lactic acidosis (a dangerous metabolic derangement), peripheral neuropathy (injury to nerves in the extremities), and lipodystrophy (cosmetically undesirable rearrangement of fat in the body). The supplement CoQ 10 has been tried for minimizing these side effects, but unexpected results occurred. In a double-blind, placebo-controlled study, use of CoQ10 improved general sense of well-being in people with HIV-infection using reverse transcriptase inhibitors; however, for reasons that are unclear, it actually worsened symptoms of peripheral neuropathy.80 For this reason, people with HIV who have peripheral neuropathy symptoms should use CoQ 10 only with caution.
The maximum safe dosages of CoQ 10 for young children, pregnant or nursing women, or those with severe liver or kidney disease have not been determined.
Interactions You Should Know About
References [ + ]
1. Weis M, Mortensen SA, Rassing MR, et al. Bioavailability of four oral coenzyme Q 10 formulations in healthy volunteers. Mol Aspects Med. 1994;15(suppl):S273.
2. Morisco C, Trimarco B, Condorelli M. Effect of coenzyme Q 10 therapy in patients with congestive heart failure: a long-term multicenter randomized study. Clin Investig. 1993;71(suppl 8):S134-S136.
3. Hashiba K, Kuramoto K, Ishimi Z, et al. Heart. 1972;4:1579-1589. Cited by: Werbach MR. Nutritional Influences on Illness [book on CD-ROM] Tarzana, CA: Third Line Press; 1998.
4. Hofman-Bang C, Rehnquist N, Swedberg K, et al. Coenzyme Q 10 as an adjunctive treatment of congestive heart failure. J Am Coll Cardiol. 1992;19:216A.
5. Langsjoen H, Langsjoen P, Langsjoen P, et al. Usefulness of coenzyme Q 10 in clinical cardiology: a long-term study. Mol Aspects Med. 1994;15(suppl):S165-S175.
6. Langsjoen PH, Vadhanavikit S, Folkers K. Response of patients in classes III and IV of cardiomyopathy to therapy in a blind and crossover trial with coenzyme Q 10. Proc Natl Acad Sci USA. 1985;82:4240-4244.
7. Pogessi L, Galanti G, Comeglio M, et al. Effect of coenzyme Q 10 on left ventricular function in patients with dilative cardiomyopathy. Curr Ther Res. 1991;49:878-886.
8. Digiesi V, Cantini F, Brodbeck B. Effect of coenzyme Q 10 on essential arterial hypertension. Curr Ther Res. 1990;47:841-845.
9. Langsjoen P, Langsjoen P, Willis R, et al. Treatment of essential hypertension with coenzyme Q 10. Mol Aspects Med. 1994;15(suppl):S265-S272.
10. Digiesi V, Cantini F, Oradei A, et al. Coenzyme Q 10 in essential hypertension. Mol Aspects Med. 1994;15(suppl):S257-S263.
11. Singh RB, Niaz MA, Rastogi SS, et al. Effect of hydrosoluble coenzyme Q 10 on blood pressures and insulin resistance in hypertensive patients with coronary artery disease. J Human Hypertens. 1999;13:203-208.
12. Watts TL. Coenzyme Q 10 and periodontal treatment: Is there any beneficial effect? Br Dent J. 1995;178:209-213.
13. Matthews RT, Yang L, Browne S, et al. Coenzyme Q10 administration increases brain mitochondrial concentrations and exerts neuroprotective effects. Proc Natl Acad Sci USA. 1998;95:8892-8897.
14. Beal MF. Coenzyme Q 10 administration and its potential for treatment of neurodegenerative diseases. Biofactors. 1999;9:261-266.
15. Ylikoski T, Piirainen J, Hanninen O, et al. The effect of coenzyme Q 10 on the exercise performance of cross-country skiers. Mol Aspects Med. 1997;18(suppl):S283-S290.
16. Zuliani U, Bonetti A, Campana M, et al. The influence of Ubiquinone (Co Q 10) on the metabolic response to work. J Sports Med Phys Fitness. 1989;29:57-62.
17. Weston SB, Zhou S, Weatherby RP, et al. Does exogenous coenzyme Q 10 affect aerobic capacity in endurance athletes? Int J Sport Nutr. 1997;7:197-206.
18. Malm C, Svensson M, Ekblom B, et al. Effects of ubiquinone-10 supplementation and high intensity training on physical performance in humans. Acta Physiol Scand. 1997;161:379-384.
19. Snider IP, Bazzarre TL, Murdoch SD, et al. Effects of coenzyme athletic performance system as an ergogenic aid on endurance performance to exhaustion. Int J Sport Nutr. 1992;2:272-286.
20. Porter DA, Costill DL, Zachwieja JJ, et al. The effect of oral coenzyme Q 10 on the exercise tolerance of middle-aged, untrained men. Int J Sports Med. 1995;16:421-427.
21. Braun B, Clarkson PM, Freedson PS, et al. Effects of coenzyme Q 10 supplementation on exercise performance, VO2max, and lipid peroxidation in trained cyclists. Int J Sport Nutr. 1991;1:353-365.
22. Bargossi AM, Grossi G, Fiorella PL, et al. Exogenous CoQ 10 supplementation prevents plasma ubiquinone reduction induced by HMG-CoA reductase inhibitors. Mol Aspects Med. 1994;15(suppl):S187-S193.
23. Ghirlanda G, Oradei A, Manto A, et al. Evidence of plasma CoQ 10 -lowering effect by HMG-CoA reductase inhibitors: a double-blind, placebo-controlled study. J Clin Pharmacol. 1993;33:226-229.
24. Mortensen SA, Leth A, Agner E, et al. Dose-related decrease of serum coenzyme Q 10 during treatment with HMG-CoA reductase inhibitors. Mol Aspects Med. 1997;18(suppl):S137-S144.
25. Folkers K, Langsjoen P, Willis R, et al. Lovastatin decreases coenzyme Q levels in humans. Proc Natl Acad Sci USA. 1990; 87:8931-8934.
26. Kishi T, Kishi H, Watanabe T, et al. Bioenergetics in clinical medicine. XI. Studies on Coenzyme Q and diabetes mellitus. J Med. 1976;7:307-321.
27. Kishi H, Kishi T, Folkers K. Bioenergetics in clinical medicine. III. Inhibition of coenzyme Q 10 -enzymes by clinically used anti-hypertensive drugs. Res Commun Chem Pathol Pharmacol. 1975;12:533-540.
28. Kishi T, Watanabe T, Folkers K. Bioenergetics in clinical medicine XV. Inhibition of coenzyme Q 10 -enzymes by clinically used adrenergic blockers of beta-receptors. Res Commun Chem Pathol Pharmacol. 1977;17:157-164.
29. Folkers K. Basic chemical research on coenzyme Q 10 and integrated clinical research on therapy of diseases. Biomed Clin Aspects Coenzyme Q. 1985;5:457-478.
30. Kishi T, Makino K, Okamoto T, et al. Inhibition of myocardial respiration by psychotherapeutic drugs and prevention by coenzyme Q. Biomed Clin Aspects Coenzyme Q. 1980;4:139-157.
31. Hamada M, Kazatain Y, Ochi T, et al. Correlation between serum CoQ 10 level and myocardial contractility in hypertensive patients. Biomed Clin Aspects Coenzyme Q. 1984;4:263-270.
32. Werbach MR. Nutritional Influences on Illness. [book on CD-ROM] Tarzana, CA: Third Line Press; 1998.
33. Morisco C, Trimarco B, Condorelli M. Effect of coenzyme Q 10 therapy in patients with congestive heart failure: a long-term multicenter randomized study. Clin Investig. 1993;71(suppl 8):S134-S136.
34. Hashiba K, Kuramoto K, Ishimi Z, et al. Heart. 1972;4:1579-1589. Cited by: Werbach MR. Nutritional Influences on Illness. [book on CD-ROM] Tarzana, CA: Third Line Press; 1998.
35. Hofman-Bang C, Rehnquist N, Swedberg K, et al. Coenzyme Q 10 as an adjunctive treatment of congestive heart failure. J Am Coll Cardiol. 1992;19:216A.
36. Khatta M, Alexander BS, Krichten CM, et al. The effect of coenzyme Q 10 in patients with congestive heart failure. Ann Intern Med. 2000;132:636-640.
37. Langsjoen H, Langsjoen P, Langsjoen P, et al. Usefulness of coenzyme Q 10 in clinical cardiology: a long-term study. Mol Aspects Med. 1994;15(suppl):S165-S175.
38. Langsjoen PH, Vadhanavikit S, Folkers K. Response of patients in classes III and IV of cardiomyopathy to therapy in a blind and crossover trial with coenzyme Q 10. Proc Natl Acad Sci USA. 1985;82:4240-4244.
39. Pogessi L, Galanti G, Comeglio M, et al. Effect of coenzyme Q 10 on left ventricular function in patients with dilative cardiomyopathy. Curr Ther Res. 1991;49:878-886.
40. Singh RB, Niaz MA, Rastogi SS, et al. Effect of hydrosoluble coenzyme Q 10 on blood pressures and insulin resistance in hypertensive patients with coronary artery disease. J Human Hypertens. 1999;13:203-208.
41. Digiesi V, Cantini F, Brodbeck B. Effect of coenzyme Q 10 on essential arterial hypertension. Curr Ther Res. 1990;47:841-845.
42. Langsjoen P, Langsjoen P, Willis R, et al. Treatment of essential hypertension with coenzyme Q 10. Mol Aspects Med. 1994;15(suppl):S265-S272.
43. Digiesi V, Cantini F, Oradei A, et al. Coenzyme Q 10 in essential hypertension. Mol Aspects Med. 1994;15(suppl):S257-S263.
44. Lampertico M, Comis S. Italian multicenter study on the efficacy and safety of coenzyme Q 10 as adjuvant therapy in heart failure. Clin Investig. 1993;71(suppl 8):S129-S133.
45. Singh RB, Niaz MA, Rastogi SS, et al. Effect of hydrosoluble coenzyme Q 10 on blood pressures and insulin resistance in hypertensive patients with coronary artery disease. J Human Hypertens. 1999;13:203-208.
46. Eriksson JG, Forsen TJ, Mortensen SA, et al. The effect of coenzyme Q 10 administration on metabolic control in patients with type 2 diabetes mellitus. Biofactors. 1999;9:315-318.
47. Spigset O. Reduced effect of warfarin caused by ubidecarenone [letter]. Lancet. 1994;344:1372-1373.
48. Huntington Study Group. A randomized, placebo-controlled trial of coenzyme Q 10 and remacemide in Huntington's disease. Neurology. 2001;57:397-404.
49. Singh RB, Khanna HK, Niaz MA. Randomized, double-blind, placebo-controlled trial of coenzyme Q10 in chronic renal failure: discovery of a new role. J Nutr Environ Med. 2000;10:281-288.
50. Burke BE, Neuenschwander R, Olson RD. Randomized, double-blind, placebo-controlled trial of coenzyme Q10 in isolated systolic hypertension. South Med J. 2001;94:1112-1117.
51. Munkholm H, Hansen HH, Rasmussen K. Coenzyme Q 10 treatment in serious heart failure. Biofactors. 1999;9:285-289.
52. Watson PS, Scalia GM, Galbraith A, et al. Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure. J Am Coll Cardiol. 1999;33:1549-1552.
53. Munkholm H, Hansen HH, Rasmussen K. Coenzyme Q 10 treatment in serious heart failure. Biofactors. 1999;9:285-289.
54. Watson PS, Scalia GM, Galbraith A, et al. Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure. J Am Coll Cardiol. 1999;33:1549-1552.
55. Combs AB, Porter TH, Folkers K. Anticoagulant activity of a naphtoquinone analog of vitamin K and an inhibitor of coenzyme Q 10 -enzyme systems. Res Commun Chem Pathol Pharmacol. 1976;13:109-114.
56. Engelsen J, Nielsen JD, Winther K. Effect of coenzyme Q 10 and Ginkgo biloba on warfarin dosage in stable, long-term warfarin-treated outpatients. A randomised, double-blind, placebo-crossover trial. Thromb Haemost. 2002;87:1075-1076.
57. Shults CW, Oakes D, Kieburtz K, et al. Effects of coenzyme q10 in early Parkinson disease: evidence of slowing of the functional decline. Arch Neurol. 2002;59:1541-1550.
58. Hodgson JM, Watts GF, Playford DA, et al. Coenzyme Q(10) improves blood pressure and glycaemic control: a controlled trial in subjects with type 2 diabetes. Eur J Clin Nutr. 2002;56:1137-1142.
59. Combs AB, Choe JY, Truong DH, et al. Reduction by coenzyme Q 10 of the acute toxicity of adriamycin in mice. Res Commun Chem Pathol Pharmacol. 1977;18:565-568.
60. Judy WV, Hall JH, Dugan W, et al. Coenzyme Q 10 reduction of Adriamycin cardiotoxicity. Biomed Clin Aspects Coenzyme Q. 1984;4:231-241.
61. Sugiyama S, Yamada K, Hayakawa M, et al. Approaches that mitigate doxorubicin-induced delayed adverse effects on mitochondrial functions in rat hearts; Liposome-encapsulated doxorubican or combination therapy with antioxidant. Biochem Mol Biol Int. 1995;36:1001-1007.
62. Eriksson JG, Forsen TJ, Mortensen SA, et al. The effect of coenzyme Q10 administration on metabolic control in patients with type 2 diabetes mellitus. Biofactors. 1999;9:315-318.
63. Singh RB, Wander GS, Rastogi A, et al. Randomized double-blind placebo-controlled trial of coenzyme Q10 in patients with acute myocardial infarction. Cardiovasc Drugs Ther. 1998;12:347-353.
64. Kuklinski B, Weissenbacher E, Fahnrich A. Coenzyme Q10 and antioxidants in acute myocardial infarction. Mol Aspects Med. 1994;15(suppl):S143-S147.
65. Muller T, Buttner T, Gholipour AF, et al. Coenzyme Q(10) supplementation provides mild symptomatic benefit in patients with Parkinson's disease. Neurosci Lett. 2003;341:201-204.
66. Berman M, Erman A, Ben-Gal T, et al. Coenzyme Q 10 in patients with end-stage heart failure awaiting cardiac transplantation: a randomized, placebo-controlled study. Clin Cardiol. 2004;27:295-299.
67. Singh RB, Neki NS, Kartikey K, et al. Effect of coenzyme Q 10 on risk of atherosclerosis in patients with recent myocardial infarction. Mol Cell Biochem. 2003;246:75-82.
68. Damian MS, Ellenberg D, Gildemeister R, et al. Coenzyme Q 10 combined with mild hypothermia after cardiac arrest. A preliminary study. Circulation. 2004 Nov 11. [Epub ahead of print]
69. Rosenfeldt F, Marasco S, Lyon W, et al. Coenzyme Q 10 therapy before cardiac surgery improves mitochondrial function and in vitro contractility of myocardial tissue. J Thorac Cardiovasc Surg. 2005;129:25-32.
70. Roffe L, Schmidt K, Ernst E, et al. Efficacy of coenzyme Q 10 for improved tolerability of cancer treatments: a systematic review. J Clin Oncol. 2004;22:4418-4424.
71. Christensen ER, Stegger M, Jensen-Fangel S, et al. Mitochondrial DNA levels in fat and blood cells from patients with lipodystrophy or peripheral neuropathy and the effect of 90 days of high-dose coenzyme Q treatment: a randomized, double-blind, placebo-controlled pilot study. Clinical Infectious Diseases. 2004;39:1371-1379.
72. Berman M, Erman A, Ben-Gal T, et al. Coenzyme Q 10 in patients with end-stage heart failure awaiting cardiac transplantation: a randomized, placebo-controlled study. Clin Cardiol. 2004;27:295-299.
73. Singh RB, Neki NS, Kartikey K, et al. Effect of coenzyme Q 10 on risk of atherosclerosis in patients with recent myocardial infarction. Mol Cell Biochem. 2003;246:75-82.
74. Damian MS, Ellenberg D, Gildemeister R, et al. Coenzyme Q 10 combined with mild hypothermia after cardiac arrest. A preliminary study. Circulation. 2004 Nov 11. [Epub ahead of print]
75. Sandor PS, Di Clemente L, Coppola G, et al. Efficacy of coenzyme Q10 in migraine prophylaxis: A randomized controlled trial. Neurology. 2005;64:713-715.
76. Stocker R, Pollicino C, Gay CA, et al. Neither plasma coenzyme Q(10) concentration, nor its decline during pravastatin therapy, is linked to recurrent cardiovascular disease events: A prospective case-control study from the LIPID study. A therosclerosis. 2005 Oct 8. [Epub ahead of print]
77. Strey CH, Young JM, Molyneux SL, et al. Endothelium-ameliorating effects of statin therapy and coenzyme Q(10) reductions in chronic heart failure. Atherosclerosis. 2005;179:201-206.
78. Zhou S, Zhang Y, Davie A, et al. Muscle and plasma coenzyme Q(10) concentration, aerobic power and exercise economy of healthy men in response to four weeks of supplementation. J Sports Med Phys Fitness. 2005;45:337-346.
79. Ikematsu H, Nakamura K, Harashima SI, et al. Safety assessment of coenzyme Q10 (Kaneka Q10) in healthy subjects: A double-blind, randomized, placebo-controlled trial. Regul Toxicol Pharmacol. 2006 Jan 20. [Epub ahead of print].
80. Christensen ER, Stegger M, Jensen-Fangel S, et al. Mitochondrial DNA levels in fat and blood cells from patients with lipodystrophy or peripheral neuropathy and the effect of 90 days of high-dose coenzyme Q treatment: a randomized, double-blind, placebo-controlled pilot study. Clinical Infectious Diseases. 2004;39:1371-1379.
81. Singh RB, Niaz MA, Kumar A, et al. Effect on absorption and oxidative stress of different oral Coenzyme Q 10 dosages and intake strategy in healthy men. Biofactors. 2006;25:219-224.
82. Gvozdjakova A, Kucharska J, Bartkovjakova M, et al. Coenzyme Q 10 supplementation reduces corticosteroids dosage in patients with bronchial asthma. Biofactors. 2006;25:235-240.
83. Belardinelli R, Mucaj A, Lacalaprice F, et al. Coenzyme Q 10 and exercise training in chronic heart failure. Eur Heart J. 2006 Aug 1. [Epub ahead of print]
84. Conklin KA. Coenzyme Q 10 for prevention of anthracycline-induced cardiotoxicity. Integr Cancer Ther. 2005;4:110-130.
85. Khan M, Gross J, Haupt H, et al. A pilot clinical trial of the effects of coenzyme Q 10 on chronic tinnitus aurium. Otolaryngol Head Neck Surg. 2007;136:72-77.
86. Storch A, Jost WH, Vieregge P, et al. Randomized, double-blind, placebo-controlled trial on symptomatic effects of coenzyme Q 10 in parkinson disease. Arch Neurol. 2007 May 14. [Epub ahead of print]
87. Marcoff L, Thompson PD. The role of coenzyme Q10 in statin-associated myopathy: a systematic review. J Am Coll Cardiol. 2007;49:2231-2237.
88. Mabuchi H, Nohara A, Kobayashi J, et al. Effects of CoQ 10 supplementation on plasma lipoprotein lipid, CoQ 10 and liver and muscle enzyme levels in hypercholesterolemic patients treated with atorvastatin: A randomized double-blind study. Atherosclerosis. 2007 Aug 4. [Epub ahead of print]
89. Yang HT, Lin SH, Huang SY, et al. Acute administration of red yeast rice ( Monascus purpureus) depletes tissue coenzyme Q(10) levels in ICR mice. Br J Nutr. 2005;93:131–135.
90. Young JM, Florkowski CM, Molyneux SL, et al. Effect of coenzyme Q(10) supplementation on simvastatin-induced myalgia. Am J Cardiol. 2007;100:1400-1403.
91. Schaars CF, Stalenhoef AF. Effects of ubiquinone (coenzyme Q 10) on myopathy in statin users. Curr Opin Lipidol. 2008;19:553-557.
92. Teran E, Hernandez I, Nieto B, Tavara R, Ocampo JE, Calle A. Coenzyme Q10 supplementation during pregnancy reduces the risk of pre-eclampsia. Int J Gynaecol Obstet. 2009;105(1):43-45.
93. Gökbel H, Gül I, Belviranl M, Okudan N. The effects of coenzyme Q10 supplementation on performance during repeated bouts of supramaximal exercise in sedentary men. J Strength Cond Res. 2010;24(1):97-102.
94. Safarinejad MR. Efficacy of coenzyme Q10 on semen parameters, sperm function and reproductive hormones in infertile men. J Urol. 2009;182(1):237-248
95. Madmani ME, Solaiman AY, et al. Coenzyme Q10 for heart failure. Cochrane Database Syst Rev. 2013;CD008684.
Last reviewed December 2015 by EBSCO CAM Review Board