Coenzyme Q10

What Are "Star" Ratings?

a7_3star Reliable and relatively consistent scientific data showing a substantial health benefit.

a7_2star Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.

a7_1star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.

Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.

For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.

This supplement has been used in connection with the following health conditions:

Used for	Amount	Why
Angina	150 mg daily	CoQ10 contributes to the heart’s energy-making mechanisms. Angina patients given CoQ10 have experienced greater ability to exercise without chest pain.
Angina 150 mg daily Coenzyme Q10 contributes to the energy-making mechanisms of the heart. Angina patients given 150 mg of coenzyme Q10 each day have experienced greater ability to exercise without experiencing chest pain.¹ This has been confirmed in independent investigations.² Learn More

Used for	Amount	Why
Heart Attack	500 to 800 mcg daily	Taking CoQ10 may help reduce complications following a heart attack.
Heart Attack 500 to 800 mcg daily Coenzyme Q10 (CoQ10) also contributes to the energy-making mechanisms of the heart and has been reported to lower lipoprotein(a), a risk factor for heart disease.³ Animal studies confirm CoQ10’s ability to protect heart muscle against reduced blood flow.⁴^{, 5} In one double-blind trial, either 120 mg of CoQ10 or placebo was given to people who had recently survived a heart attack. After 28 days, the CoQ10 group had experienced significantly fewer repeat heart attacks, fewer deaths from heart disease, and less chest pain than the placebo group.⁶ In another double-blind study of people suffering a heart attack, supplementation with 60 mg of coenzyme Q10 twice a day for one year significantly reduced the incidence of recurrent cardiac events (fatal or non-fatal heart attack). ⁷ Treatment was begun within 72 hours of the onset of the heart attack. CoQ10 used with selenium (see below) has also been reported to increase the rate of heart attack survival.⁸ The relation between selenium and protection from heart attacks remains uncertain. Low blood levels of selenium have been reported in people immediately following a heart attack,⁹ suggesting that heart attacks may increase the need for selenium. However, other researchers claim that low selenium levels are present in people before they have a heart attack, suggesting that the lack of selenium might increase heart attack risk.¹⁰ One report found that low blood levels of selenium increased the risk of heart attack only in smokers,¹¹ and another found the link only in former smokers.¹² Yet others have found no link between low blood levels of selenium and heart attack risk whatsoever.¹³ In a double-blind trial, individuals who already had one heart attack were given 100 mcg of selenium per day or placebo for six months.¹⁴ At the end of the trial, there were four deaths from heart disease in the placebo group but none in the selenium group (although the numbers were too small for this difference to be statistically significant). In other controlled research, a similar group was given placebo or 500 mcg of selenium six hours or less after a heart attack followed by an ongoing regimen of 100 mcg of selenium plus 100 mg of coenzyme Q10 per day.¹⁵ One year later, six people had died from a repeat heart attack in the placebo group, compared with no heart attack deaths in the supplement group. Despite the lack of consistency in published research, some doctors recommend that people at risk for a heart attack supplement with selenium—most commonly 200 mcg per day. Learn More

Used for	Amount	Why
Hypertension	100 mg twice per day	Taking coenzyme Q10 may have a significant impact on blood pressure.
Hypertension 100 mg twice per day Both preliminary¹⁶ ^{, 17} ^{, 18} and double-blind¹⁹ ^{, 20} trials have reported that supplementation with coenzyme Q10 (CoQ10) leads to a significant decrease in blood pressure in people with hypertension. Much of this research has used 100 mg of CoQ10 per day for at least ten weeks. Learn More

Used for	Amount	Why
Athletic Performance	Refer to label instructions	Strenuous physical activity lowers blood levels of coenzyme Q10 (CoQ10). A few studies have reported that CoQ10 supplementation benefitted some trained athletes.
Athletic Performance Strenuous physical activity lowers blood levels of coenzyme Q10 (CoQ10).²¹ However, while some studies have shown that CoQ10 improves the way the healthy body responds to exercise,²² other studies have found no improvement.²³ ^{, 24} ^{, 25} ^{, 26} A few studies, using at least four weeks of CoQ10 supplementation at 60 to 100 mg per day, have reported improvements in measures of work capacity ranging from 3 to 29% in sedentary people and from 4 to 32% in trained athletes.²⁷ However, recent double-blind and/or placebo-controlled trials in trained athletes, using performance measures such as time to exhaustion and total performance, have found either no significant improvement or significantly poorer results in those taking CoQ10.²⁸ ^{, 29} ^{, 30} Learn More

Used for	Amount	Why
Cardiomyopathy	100 to 150 mg daily	Most studies using coenzyme Q10 in treating cardiomyopathy have shown positive results, including improved quality of life, heart function tests, and survival rates.
Cardiomyopathy 100 to 150 mg daily People with dilated congestive cardiomyopathy (DCM) have been shown to be deficient in coenzyme Q10.³¹ Most studies using coenzyme Q10 in the treatment of cardiomyopathy have demonstrated positive results, including improved quality of life, heart function tests, and survival rates.³² ^{, 33} ^{, 34} Coenzyme Q10 also has been shown to improve cardiac function in people with hypertrophic cardiomyopathy—a less common form of cardiomyopathy.³⁵ A few studies, however, have found no benefit from CoQ10 supplementation in treating people with cardiomyopathy.³⁶ ^{, 37} Despite a lack of consistency in the outcomes of published research, many doctors recommend that 100 to 150 mg be taken each day, with meals. Learn More

Used for	Amount	Why
Congestive Heart Failure	0.9 mg daily per pound of body weight with a doctor's supervision	CoQ10 enhances the production of energy in the heart muscle and has been reported to help people with CHF, sometimes dramatically.
Congestive Heart Failure 0.9 mg daily per pound of body weight with a doctor's supervision As is true for several other heart conditions, coenzyme Q10 (CoQ10) has been reported to help people with congestive heart failure,³⁸ ^{, 39} sometimes dramatically.⁴⁰ Positive effects have been confirmed in double-blind research⁴¹ and in an overall analysis of eight controlled trials.⁴² However, some double-blind trials have reported modest⁴³ or no improvement⁴⁴ ^{, 45} ^{, 46} in exercise capacity or overall quality of life. Most CoQ10 research used 90–200 mg per day. The beneficial effects of CoQ10 may not be seen until after several months of treatment. Discontinuation of CoQ10 supplementation in people with congestive heart failure has resulted in severe relapses and should only be attempted under the supervision of a doctor.⁴⁷ Learn More

Used for	Amount	Why
Gingivitis	50 to 60 mg daily	Supplementing with CoQ10 may reduce gingivitis symptoms and repair damaged gum tissues.
Gingivitis 50 to 60 mg daily Preliminary evidence has linked gingivitis to a coenzyme Q10 (CoQ10) deficiency.⁴⁸ Some researchers believe this deficiency could interfere with the body’s ability to repair damaged gum tissue. In a double-blind trial, 50 mg per day of CoQ10 given for three weeks was significantly more effective than a placebo at reducing symptoms of gingivitis.⁴⁹ Compared with conventional approaches alone, topical CoQ10 combined with conventional treatments resulted in better outcomes in a group of people with periodontal disease.⁵⁰ Learn More

Used for	Amount	Why
Halitosis and Gum Disease	50 to 60 mg daily	Coenzyme Q10 is often recommended by doctors to help prevent and treat periodontitis.
Halitosis and Gum Disease 50 to 60 mg daily Nutritional supplements recommended by some doctors for prevention and treatment of periodontitis include vitamin C (people with periodontitis are often found to be deficient),⁵¹ vitamin E, selenium, zinc, coenzyme Q10, and folic acid.⁵² Folic acid has also been shown to reduce the severity of gingivitis when taken as a mouthwash.⁵³

Used for	Amount	Why
Macular Degeneration (Acetyl-L-Carnitine, Fish Oil)	Follow label directions	In one study, supplementing with a proprietary blend of acetyl-L-carnitine, fish oil, and coenzyme Q10 improved visual function in people with macular degeneration.
Macular Degeneration Follow label directions In a double-blind study, supplementation with a proprietary blend of acetyl-L-carnitine, omega-3 fatty acids from fish oil, and coenzyme Q10 for 12 months resulted in an improvement in both visual function and in objective findings on eye examination (a decrease in the drusen-covered area on the retina).⁵⁴ Learn More

Used for	Amount	Why
Migraine Headache	100 to 150 mg daily	In a preliminary trial, supplementation with coenzyme Q10 for three months reduced the average number of days with migraine headaches by 60%.
Migraine Headache 100 to 150 mg daily Blood levels of coenzyme Q10 have been found to be low in about one-third of migraine sufferers.⁵⁵ In a preliminary trial, supplementation of migraine sufferers with 150 mg per day of coenzyme Q10 for three months reduced the average number of days with migraine headaches by 60%.⁵⁶ The beneficial effect of coenzyme Q10 was confirmed in a four-month double-blind study. By the fourth month of treatment, a reduction in migraine frequency of 50% or greater occurred in 47.6% of people receiving 100 mg of coenzyme Q10 three times a day, but in only 14.4% of those receiving a placebo (a statistically significant difference).⁵⁷ Learn More

Used for	Amount	Why
Parkinson’s Disease	1,200 mg a day	In a double-blind trial, coenzyme Q10 given to people with early Parkinson's disease significantly slowed the progression of the disease.
Parkinson’s Disease 1,200 mg a day In a double-blind trial, administration of 1,200 mg of coenzyme Q10 per day for 16 months to people with early Parkinson's disease significantly slowed the progression of the disease, compared with a placebo.⁵⁸ Smaller amounts of CoQ10 were slightly more effective than placebo, but the difference was not statistically significant. Learn More

Used for	Amount	Why
Preeclampsia	200 mg per day	In a double-blind study at women who were at high risk of developing preeclampsia, supplementing with coenzyme Q10 reduced the incidence of preeclampsia by 44%.
Preeclampsia 200 mg per day Pregnant women with preeclampsia have significantly lower plasma coenzyme Q10 levels, when compared with women with healthy pregnancies. In a double-blind study at women who were at high risk of developing preeclampsia, supplementing with coenzyme Q10 reduced the incidence of preeclampsia by 44%. The amount used was 200 mg per day; treatment was begun during the twentieth week of pregnancy and continued until delivery.⁵⁹ Learn More

Used for	Amount	Why
Type 2 Diabetes	120 mg daily of a standardized herbal extract	Supplementing with CoQ10 may improve blood sugar metabolism.
Type 2 Diabetes 120 mg daily of a standardized herbal extract Coenzyme Q10 (CoQ10) is needed for normal blood sugar metabolism. Animals with diabetes have been reported to be CoQ10 deficient. People with type 2 diabetes have been found to have significantly lower blood levels of CoQ10 compared with healthy people.⁶⁰ In one trial, blood sugar levels fell substantially in 31% of people with diabetes after they supplemented with 120 mg per day of CoQ7, a substance similar to CoQ10.⁶¹ The importance of CoQ10 supplementation for people with diabetes remains an unresolved issue, though some doctors recommend approximately 50 mg per day as a way to protect against possible effects associated with diabetes-induced depletion. Learn More

Used for	Amount	Why
Alzheimer’s Disease (Iron, Vitamin B6)	Refer to label instructions	A combination of coenzyme Q10, iron (sodium ferrous citrate), and vitamin B6 may improve mental status in people with Alzheimer’s disease.
Alzheimer’s Disease In a preliminary report, two people with a hereditary form of Alzheimer’s disease received daily: coenzyme Q10 (60 mg), iron (150 mg of sodium ferrous citrate), and vitamin B6 (180 mg). Mental status improved in both patients, and one became almost normal after six months.⁶² Learn More

Used for	Amount	Why
Breast Cancer	Refer to label instructions	Some studies have found that women who take CoQ10 have a greater chance of remaining cancer-free after breast-cancer treatment.
Breast Cancer French researchers have reported that the lower the blood level of CoQ10 in breast cancer patients, the worse the chance of remaining free of disease.⁶³ For several years, researchers from Denmark and the United States have been studying the effects CoQ10 in a group of 32 breast cancer patients who were either at high risk of suffering a recurrence or had already been diagnosed with advanced disease.⁶⁴ After 18 months, only one patient had suffered a recurrence, all were still alive, those who did not have advanced disease at the beginning of the trial had not progressed to advanced disease, one patient with advanced disease had stabilized, and two patients with advanced disease had significantly improved.⁶⁵ Patients continued to do well after two years of supplementation,⁶⁶ and after three to five years, surprising improvements were reported in two patients who had had advanced disease at the beginning of the trial.⁶⁷ At first, 90 mg of CoQ10 per day was used. In subsequent reports, the amount of CoQ10 was increased until some women were receiving 390 mg per day.⁶⁸ Initially, the CoQ10 was accompanied by the use of many other supplements.⁶⁹ The researchers of this trial have attributed the therapeutic effects observed primarily to CoQ10 and, in later reports, no further mention of other supplements was made.⁷⁰ ^{, 71} ^{, 72} This preliminary investigation has been conducted with no control group, and published reports have provided only sketchy details about the conditions of most of the women being studied. Some of the patients were given conventional treatments along with CoQ10. Therefore, CoQ10 remains unproven as a cancer treatment. Learn More

Used for	Amount	Why
Chronic Obstructive Pulmonary Disease	Refer to label instructions	CoQ10 levels have been found to be low in people with COPD. Supplementing with CoQ10 improved blood oxygenation, exercise performance, and heart rate in one study.
Chronic Obstructive Pulmonary Disease Researchers have also given coenzyme Q10 (CoQ10) to people with COPD after discovering their blood levels of CoQ10 were lower than those found in healthy people.⁷³ In that trial, 90 mg of CoQ10 per day, given for eight weeks, led to no change in lung function, though oxygenation of blood improved, as did exercise performance and heart rate. Until more research is done, the importance of supplementing with CoQ10 for people with COPD remains unclear. Learn More

Used for	Amount	Why
HIV and AIDS Support	Refer to label instructions	In one trial, people with HIV who took CoQ10 experienced no further infections for up to seven months, and counts of infection-fighting white blood cells improved in some cases.
HIV and AIDS Support Blood levels of coenzyme Q10 (CoQ10) were also found to be low in people with HIV infection or AIDS. In a small preliminary trial, people with HIV infection took 200 mg per day of CoQ10. Eighty-three percent of these people experienced no further infections for up to seven months, and the counts of infection-fighting white blood cells improved in three cases.⁷⁴ Learn More

Used for	Amount	Why
Insulin Resistance Syndrome	Refer to label instructions	Coenzyme Q10 may improve insulin sensitivity in people with components of IRS.
Insulin Resistance Syndrome A double-blind trial showed that coenzyme Q10, 120 mg per day, reduced glucose and insulin blood levels in people with high blood pressure and heart disease.⁷⁵ These results suggest that coenzyme Q10 may improve insulin sensitivity in people with components of IRS, but more research is needed. Learn More

Used for	Amount	Why
Lung Cancer	Refer to label instructions	In an unpublished report, 4 of 11 lung cancer patients were said to be alive following ten years of daily CoQ10 supplementation.
Lung Cancer In an unpublished report, 4 of 11 lung cancer patients were said to be alive following ten years of supplementation with 100 mg of coenzyme Q10 per day.⁷⁶ Such undocumented case reports require confirmation from published research trials. Learn More

Used for	Amount	Why
Male Infertility	Refer to label instructions	CoQ10 is a nutrient used by the body to produce energy. While its exact role in the formation of sperm is unknown, even small amounts appear to increase sperm count and motility.
Male Infertility Coenzyme Q10 (CoQ10) is a nutrient used by the body in the production of energy. While its exact role in the formation of sperm is unknown, there is evidence that as little as 10 mg per day (over a two-week period) will increase sperm count and motility.⁷⁷ In one study, men with low sperm counts were given CoQ10 (60 mg per day for about three months). No significant change was noted in most sperm parameters, but a significant improvement was noted in in-vitro fertilization rates.⁷⁸ Learn More

Used for	Amount	Why
Prostate Cancer	600 mg daily	Supplementing with CoQ10 may reduce levels of PSA—a marker of cancer activity.
Prostate Cancer 600 mg daily In an unpublished report, after one year, 10 of 15 prostate cancer patients experienced a 78% decrease in the level of PSA—a marker of cancer activity.⁷⁹ The amount of coenzyme Q10 given to these men was 600 mg per day; after four months, PSA scores began to decline.⁸⁰ Such undocumented case reports require confirmation from published research trials. Learn More

Used for	Amount	Why
Tinnitus	Refer to label instructions	For people who are deficient in CoQ10, supplementing with the nutrient may improve tinnitus.
Tinnitus In a preliminary trial, supplementation with coenzyme Q10 (CoQ10) in the amount of 100 mg three times per day for 16 weeks significantly improved tinnitus in people who had initially low blood levels of CoQ10. However, CoQ10 was not beneficial for people whose initial blood levels were not low.⁸¹ Learn More

Used for	Amount	Why
Type 1 Diabetes	Refer to label instructions	Supplementing with CoQ10 may improve blood sugar metabolism.
Type 1 Diabetes Coenzyme Q10 (CoQ10) is needed for normal blood sugar metabolism. Animals with diabetes have been reported to be CoQ10 deficient. In one trial, blood sugar levels fell substantially in 31% of people with diabetes after they supplemented with 120 mg per day of CoQ7, a substance similar to CoQ10.⁸² In people with type 1 diabetes, however, supplementation with 100 mg of CoQ10 per day for three months neither improved glucose control nor reduced the need for insulin.⁸³ The importance of CoQ10 supplementation for people with diabetes remains an unresolved issue, though some doctors recommend approximately 50 mg per day as a way to protect against possible effects associated with diabetes-induced depletion. Learn More

Also indexed as:

Coenzyme Q10,
CoQ10,
q10,
ubidecarenone,
ubiquinone,
vitamin Q10

About this treatment

How to Use It

Adult levels of supplementation are usually 30–90 mg per day, although people with specific health conditions may supplement with higher levels (with the involvement of a physician). Most of the research on heart conditions has used 90–150 mg of CoQ10 per day. People with cancer who consider taking much higher amounts should discuss this issue with a doctor before supplementing. There are several anecdotal reports of large amounts of CoQ10 resulting in improvements in certain types of cancer. However, controlled trials are needed to confirm these preliminary observations. Most doctors recommend that CoQ10 be taken with meals to improve absorption.

Where to Find It

CoQ10 is found primarily in fish and meat, but the amounts in food are far less than what can be obtained from supplements.

Possible Deficiencies

Deficiency is poorly understood, but it may be caused by synthesis problems in the body rather than an insufficiency in the diet. Low blood levels have been reported in people with heart failure, cardiomyopathy, gingivitis (inflammation of the gums), morbid obesity, hypertension, muscular dystrophy, diabetes, AIDS, and in some people on kidney dialysis. People with phenylketonuria (PKU) may be deficient in CoQ10 because of dietary restrictions. CoQ10 levels are also generally lower in older people. The test used to assess CoQ10 status is not routinely available from medical laboratories.

Best Form to Take

Some, but not all, research suggests that a fat-soluble form of CoQ10 is absorbed better than CoQ10 in granular (powder) form.

Interactions

Last Review: 05-11-2011

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The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2011.

© 1995-2011 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated. This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

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