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Dr. Tori Hudson, Portland, Oregon, Blog Healthline Blog

by Tori Hudson, N.D.

CoQ-10 is one of those nutrients that just keeps surprising you- with it’s diversity, it’s benefits, safety, and research. CoQ-10 is less commonly known as ubiquinone and is widely found in nature where it is synthesized in humans, animals, plants and microbes. It is an essential component of the mitochondria, which is the energy producing unit of each cell of our body. CoQ10 is involved in the manufacture of ATP, which is similar to the energy a spark plug provides in a car engine. The cells of our body need that initial spark provided by CoQ10, in order to function.

The main beneficial effects of CoQ10 are related to its ability to improve energy production and its antioxidant properties. The antioxidant activity of CoQ10 protects against lipid peroxidation and works together with vitamin E in preventing damage to lipid membranes and plasma lipids. It also may offer some protection against atherosclerosis by preventing lipid peroxide formation and LDL cholesterol oxidation.1,2,3,4,5

The main clinical and medicinal uses of CoQ10 are cardiovascular diseases including congestive heart failure, high blood pressure, mitral valve prolapse, angina and coronary artery disease. Other uses are in diabetes, periodontal disease, immune deficiency, chronic fatigue, cancer, weight-loss, neurological disorders, male infertility and to enhance athletic performance.


The depth and breadth of the role and impact of CoQ10 on cardiac disorders is impressive. A meta-analysis of the main placebo-controlled clinical trials for about ten years concluded that dozens of parameters of cardiac function were significantly better in patients who received supplemental CoQ10. Approximately 73 percent of CoQ10 patients had improvements in cardiac output (P<.05), 76% (P <.005) had an increase in stroke volume, there was an 87% improvement in cardiac index (P<.001), the diastolic index improved in 88% (P<.001), and the ejection fraction improved in 92% (P<.001).Soja A, Mortensen S. Treatment of congestive heart failure with coenzyme Q10 illuminated by meta-analysis of clinical trials. Mol Aspects Med. 1997;18 (Suppl): S159-S168. Hypertension: How CoQ10 lowers blood pressure is not clear. It may work via stabilizing the vascular membrane and its antioxidant properties thereby reducing peripheral resistance. We do know that a deficiency of CoQ10 is present in about 39 % of patients with high blood pressure. Several studies have demonstrated that CoQ10 lowers blood pressure in patients with hypertension.6,7,8 Typically, this can take 4 to 12 weeks and should be considered to have a modest effect in individuals with hypertension, lowering the systolic and diastolic pressure about ten percent. Mitral valve prolapse: Mitral valve prolapse is more common in women, and while often is assymptomatic it can manifests as fatigue, chest pain, shortness of breath, arrhythmia and a heart murmur. Cardiomyopathy: Cardiomyopathy is a disease of heart muscle that reduces the force of the heart muscle contractions and unfavorably altering blood circulation. Most individuals with cardiomyopathy, no matter the cause, have a deficiency of CoQ10 in their blood and heart muscle tissue.9 Several clinical trials cardiomyopathy patients show significant benefit with supplementing CoQ10. In one study, 100 mg per day for 12 weeks increased cardiac ejection fraction, reduced shortness of breath and increased cardiac muscle strength.10 89 percent of the patients improved while they were on CoQ10. It is important to note from that study that when the CoQ10 was discontinued, cardiac function deteriorated. Congestive Heart Failure: Congestive heart failure (CHF) typically occurs due to the chronic effects of high blood pressure, heart valve disorders and cardiomyopathy. An inability of the heart to properly pump blood leads to arrhythmias, pulmonary edema, peripheral edema and other complications. Several studies show CoQ10 supplementation is very effective in the treatment of congestive heart failure. In the largest study, of 2,664 patients, 78 percent of the patients receiving a daily dose of 50 mg to 150 mg per day, had 63 percent or more improvements in their clinical signs and symptoms after 3 months.11 With a comforting list of positive studies, a more recent randomized, double-blind, controlled trial, the effect of CoQ10 in 55 patients with CHF did not improve ejection fraction, exercise duration or peak oxygen consumption.12 Symptomatic issues were not monitored in this study. Angina: Angina is caused by compromised blood flow to the heart as a result of atherosclerosis of the coronary arteries. When the blood and oxygen to the heart are decreased, the heart muscle suffers from ischemia and results in a squeezing or pressure pain in the chest. Several small studies have shown that CoQ10 is effective in angina patients. Small but positive studies have demonstrated a significant increase in treadmill exercise tolerance and the time of onset of chest pain and abnormal EKG findings indicative of ischemia.13

Endocrine Disorders

Diabetes: There appears to be several ways that CoQ10 can be helpful in patients with diabetes. For those on oral medications to lower blood glucose, CoQ 10 deficiency may exist in about 20 percent.14 It is thought that these medications interfere with CoQ10 metabolism. CoQ10 supplementation (150 mg /day) has also been shown to significantly improve the insulin secretion response in diabetics with certain types of mitochondrial DNA mutations15 As low as 30 mg per day has been reported to stimulate insulin synthesis and the utilization of glucose peripherally while also decreasing fasting blood sugar levels in diabetics.16

Reproductive: Selected male patients with infertility may benefit from CoQ10 supplementation. Men with too few sperm and varicocles appear to have lower levels of cellular CoQ-10.17 It may be that CoQ-10 concentrations within the cells prevent oxidative damage to sperm cells. Fertilization rates following in vitro fertilization may also benefit men with low fertilization rates. 17 men had significant improvement in their fertilzation rates after taking 60 mg per day of CoQ-10 with a 10 percent fertilization rate before treatment and a 26 percent rate following treatment.18


Immune Modulation: Chronic infections, chronic diseases reflecting impaired immunity such as heart disease, thyroiditis, cancers and allergies reflect tissues and cells with altered immune function which are highly energy-dependent. Since CoQ-10 is an essential component of the mitochondria in each cell in our body, an adequate supply of CQ-10 is required for optimal function, and optimal immune function. Several studies have been able to demonstrate an immune enhancing effect of coQ-10. 19,20,21,22,23,24,25

Cancer: Free radical formation is implicated in the development of cancer. Because of its immune enhancing and antioxidant effects, CoQ-10 should be a strong consideration for cancer patients, and especially those receiving medications which produce free radical damage. There have been very few studies on CoQ-10 and cancer patients. In one of the few, 32 women with breast cancer with at least a stage II (positive lymph nodes for malignancy), were studied for 18 months using CoQ-10 along with their conventional cancer treatment and additional antioxidants.26 Less than the expected number of patients died during the 18 months, there was no progression of distant metastasis, improvements in quality of life, and six patients showed partial remissions. A percentage of cancer patients have marked deficiencies of CoQ-10 in their serum. 26

One of the main uses of CoQ-10 in cancer is with those patients receiving cardiotoxic chemotherapeutic drugs. CoQ-10 supplementation during epirubicin chemotherapy for breast cancer was associated with an improvement of epirubicin-induced cardiac dysfunction.27 In addition, treatment with CoQ-10 after discontinuation of chemotherapy has been associated with an ability to partially reverse adriamycin-induced cardiotoxicity.28


There is some data, case examples and observations that CoQ-10 supplementation may be able to enhance athletic performance, reduce recovery time, Parkinson’s disease, Huntington’s disease, weight loss and HIV/AIDS. Much more research will need to be done in these areas to confirm theories and case examples.


Common clinical dosages range from 60 mg to as much as 300 mg although most studies used a dosage of 100 mg per day. Higher doses of 200mg to 300 mg should be used for severe heart disease, cancer patients, and other seriously ill individuals.


No serious adverse effects and no toxicities have been reported in studies lasting up to a year. Doses greater than 300 mg may have asymptomatic elevations of liver function tests. Liver disease has not been reported. Co Q10 can cause mild side effects including gastric symptoms (0.39%), nausea (0.16%), diarrhea (0.12%), and loss of appetite (0.23%). These rare effects can be minimized if doses do not exceed 100 mg in one dosing. For higher doses, use 100 mg 2-3 times per day. Safety with pregnancy and lactation has not been proven and CoQ10 should not be used during these times except when determined by a physician that the benefits outweigh the unknown risks.

Drug Interactions

CoQ10 may have an additive effects with medications used for hypertension. May reduce cardiac toxicity that can be caused by Adriamycin. May decrease insulin requirement in diabetics on insulin. Concomitant use with Coumadin may reduce the anticoagulation effects of warfarin. Four cases of decresed Coumadin efficacy have been thought to be due to CoQ10. Beta blockers may reduce serum CoQ10 levels Statins can reduce serum CoQ10 levels. Some oral hypoglycemic agents can reduce CoQ10 levels.


Preclinical and clinical studies lead us to many therapeutic applications for the use of CoQ-10 supplementation. As we gain greater understanding in the roles of inflammation, oxidative damage, and nutrient deficiencies in the development of chronic diseases, we will increasingly know how best to use CoQ-10 as a preventive and treatment measure. There is currently a strong basis for clinical use in cardiovascular disorders, immune dysfunction, cancer, diabetes, and male infertility.

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