Coenzyme Q10 (CoQ10) is a molecule found in almost all human cells, particularly those in the liver, kidneys, heart and pancreas.
It is a fat-soluble compound that functions like a vitamin and is essential for survival. Because it can be produced in the body and does not necessarily need to be supplemented, it is not classified as a true vitamin.
The structure of CoQ10 is similar to that of vitamin K. The “Q10” in its name refers to its composition of 10 isoprenoid units that are attached to a quinine ring. [1]
Its main functions include combating free radical damage as an antioxidant, stabilizing the structure of cells, and acting as a cofactor in the production of the body’s primary fuel source, adenosine triphosphate (ATP). [1, 2]
CoQ10 supplements are commonly taken to support cognitive function, heart health, metabolic processes and to prevent migraine headaches. Levels of this compound tend to decline with aging, which is why it is commonly used as a longevity supplement.
This article will discuss how Coenzyme Q10 works in the body, common uses, health benefits, food and supplement sources, safety and side effects, and potential interactions with drugs and other supplements.



- Aids in cellular energy production
- Effective anti-oxidant to combat aging
- Supports cognitive performance & wellbeing
How Does Coenzyme Q10 Work Inside the Body?
Coenzyme Q10 is an antioxidant nutrient that serves as a cofactor for a number of biological processes.
In the human body, protein compounds that exhibit biological activities are commonly called enzymes.
Coenzymes do not contain protein but are needed for protein-based enzymes to carry out their biological activities.
Coenzymes are also commonly called cofactors. They can be either chemical compounds, or metallic ions. Coenzymes assist enzymes in carrying out numerous functions inside the body.
Mitochondria are double-membrane organelles found commonly in almost all cells. They are commonly called the “powerhouse” of cells and are involved in energy production and cellular respiration.
Research shows that CoQ10 is used inside cellular mitochondria to produce energy. This coenzyme is necessary for the production of ATP inside mitochondria. ATP is the primary source of cellular energy in the body.
The body also uses CoQ10 to maintain blood vessels, enhance blood flow, reduce and repair oxidative damage, lower low-density lipoprotein (LDL) cholesterol, and inhibit accumulations of plaque inside the arteries. [1]
Like resveratrol and grape seed extract, coenzyme Q10 helps to maintain blood vessel function and enhance blood flow. Exactly how this occurs is not completely understood, but researchers believe it has to do with preserving nitric oxide, as well as through its antioxidant properties. [1, 2]
Most of the health benefits associated with this nutrient are attributed to its antioxidant effects.
By preventing and helping to repair oxidative damage to cells throughout the body, it might to reduce the risks for developing various health conditions. [1, 2]
Effects of Supplementation
The NMCD states that those with the lowest initial levels of CoQ10 seem to benefit most from its supplementation. People with sufficient initial levels may not experience any benefits from supplementation. [1]
Some health conditions marked by low endogenous levels include congestive heart failure (CHF), fibromyalgia, hypertension (high blood pressure), AIDS, some muscle diseases, and periodontal disease. [1, 2]
The endothelium is a single-layer tissue that lines the insides of blood vessels, the heart muscle, lymphatic vessels, and various other organs and cavities inside the body.
Preliminary evidence from animal studies suggests that supplemental coenzyme Q10 might increase endothelium-independent relaxation of arteries. It may also enhance endothelium-dependent vasodilation (opening) of blood vessels. [1, 2]
By relaxing and dilating blood vessels to facilitate blood delivery, Coenzyme Q10 may lower systolic blood pressure and peripheral arterial resistance. [1, 2]
Researchers believe these effects may be caused by CoQ10’s capacity to stimulate production of endothelial prostacyclin (PGI2), a known vasodilator and anticoagulant. [1]
This nutrient is also thought to increase arterial smooth muscle sensitivity to PGI2, possibly adding to the blood pressure and peripheral arterial resistance-lowering effects. [1]
In human research, supplementation with this cofactor has been shown to increase levels of the “good” type of cholesterol, high-density lipoprotein (HDL) cholesterol. It has also been shown to increase levels of vitamins C and E, two other known antioxidants. [1]
It has been shown to lower the “bad” type of cholesterol, low density lipoprotein (LDL) cholesterol. [1]
In human trials, CoQ10 has also been observed to reduce levels of thiobarbituric acid reactive substances (TBARS), diene conjugates, malondialdehyde, and other products that result from lipid peroxidation (the oxidative degradation of fats). [1]
There is some preliminary evidence that supplementing with this compound may have antiaging effects.
Research has shown that CoQ10 levels peak during the first 20 years of life, and then begin to fall off gradually in most humans. The NMCD states that by age 80, levels of this nutrient may drop to below those of a newborn. [1]
A preliminary human study found that Coenzyme Q10 may inhibit activity of ECTO-NOX (arNOX), an enzyme that increases in activity after age 30 and is believed to cause an aging cascade in cells by generating the free radical superoxide. [1]
Common CoQ10 Supplement Uses
The NMCD reports various oral uses for CoQ10 supplements including:
- Angina (severe chest pain)
- Autism
- Breast cancer
- Chronic fatigue syndrome (CFS)
- Congestive heart failure (CHF)
- Diabetes
- Hypertension (high blood pressure)
- Increasing exercise tolerance
- Periodontal disease
- Statin-induced myopathy (muscle pain or dysfunction)
- Supporting immune function in those with HIV/AIDS [1]
Coenzyme Q10 is also used orally for heart muscle toxicity resulting from doxorubicin chemotherapy treatments, Huntington’s disease, Parkinson’s disease, and muscular dystrophy.
This supplement is also used orally for Lyme disease, pre-eclampsia, migraine headache, male infertility, aging skin, and extending lifespan. [1]
In Japan, it is commonly used for cardiovascular conditions including CHF, angina, hypertrophic cardiomyopathy, and dilated cardiomyopathy. [1]
Health Benefits
The NMCD rates this supplement as Likely Effective for alleviating Coenzyme Q10 deficiency.
It is also rated Likely Effective for mitochondrial encephalomyopathies, which refer to a number of genetic and acquired disorders of mitochondrial dysfunction. [1]
The NMCD also rates this compound as Possibly Effective for:
- Age-related macular degeneration (AMD)
- Cardiovascular mortality
- Congestive heart failure (CHF)
- Diabetic neuropathy (nerve pain)
- Fibromyalgia
- HIV/AIDS immune function
- Huntington’s disease
- Ischemic reperfusion injury (tissue damage due to lack of oxygen)
- Isolated systolic hypertension
- Migraine headache
- Muscular dystrophy
- Myocardial infarction (heart attack)
- Peyronie’s disease [1]
The supplemental use of Coenzyme Q10 is being studied for many different conditions.
Research in humans is limited, but some promising results have been seen in studies on angina, autism, bipolar disorder, cancer, cyclic vomiting syndrome (CVS), hypertension, male infertility, Parkinson’s disease, pre-eclampsia, and statin-induced myopathy.
More research is still needed to determine the therapeutic efficacy of CoQ10 for these and other conditions.
Coenzyme Q10 is regulated as a dietary supplement and the FDA has not approved it as a drug to prevent or treat any medical conditions.
Congestive Heart Failure
The University of Maryland Medical Center (UMM) states that CoQ10 may be helpful for treating heart failure, especially when used as an adjunct therapy to treatment with conventional medications. [3]
Congestive heart failure (CHF) is a chronic condition that affects the chambers of the heart muscle, causing the heart to not be able to pump blood efficiently.
This can cause blood and other fluids to accumulate and pool in parts of the body, particularly in the legs, abdomen, liver, and lungs.
CHF can cause symptoms including labored breathing, chronic fatigue, irregular heartbeat, swelling in the limbs, coughing, pulmonary edema, fainting, and others.
According to the NMCD, multiple research studies have found that adding Coenzyme Q10 supplements to traditional treatments can improve quality of life.
It has been shown to, “improve New York Heart Association (NYHA) classification, decrease hospitalization rates, and decrease symptoms of heart failure such as dyspnea, peripheral edema, enlarged liver, and insomnia in patients with mild to severe … CHF.” [1]
Accruing to UMM, several studies have shown supplemental CoQ10 to improve exercise capacity, relax breathing, reduce lung fluids, and decrease swelling in people with heart failure. [3]
Some research suggests that taking between 100 and 300 mg of CoQ10 daily for up to 7 months can improve CHF markers including left ventricular ejection fraction, systolic wall thickening and cardiac output. [1]
Not all studies have yielded positive results. Some studies showed no effects from using supplements in CHF patients. [3, 4]
The NMCD states that low CoQ10 levels might be associated with heart failure. However, it is not currently understood if low levels are a causal factor or if heart failure depletes levels of this nutrient. [1]
Overall, the evidence for using CoQ10 for CHF is promising, but conflicting evidence exists. The strongest evidence for benefits are seen when it is used as an adjunct treatment in conjunction with traditional treatments.
According to NMCD, “there is no strong evidence that coenzyme Q10 can help heart failure when taken alone, but it might be helpful when taken with other heart failure drugs.” [1]
Speak with your doctor if you are interested in learning more about Coenzyme Q10 and CHF. Your doctor will be able to determine if this supplement is right for your needs.
Heart Health
CoQ10 is commonly used to promote cardiovascular health and circulatory function.
In one study, first-time heart attack patients were found to be less likely to have subsequent heart attacks, and/or chest pain, if they began using a CoQ10 supplement within 3 days.
These patients were also less likely to die because of heart disease compared to patients who did not receive supplements. [3]
Another study found benefits in patients who had a heart attack and received cardiopulmonary resuscitation (CPR).
A single initial loading dose of 250 mg Coenzyme Q10 followed by three daily doses of 150 mg for five days through a nasogastric tube improved 3-month survival rate by 134% compared to patients give a placebo. [1]
Research on CoQ10 for heart attacks is limited, and more clinical research is still needed.
If you are interested in taking this supplement, it is recommended to speak with your doctor before beginning use especially if you have a history of heart problems.
Clinical research shows that taking CoQ10 before heart transplantation or bypass surgery can decrease free radical damage, improve cardiac function, and lower the chances for arrhythmias while recovering. [6]
The decision to use this product before a heart surgery should be made by a cardiologist. Ask your doctor about the safety of using Coenzyme Q10 before any heart surgery you may be scheduled for.
Anthracycline chemotherapy drugs like doxorubicin (adriamycin), and some other chemotherapy drugs are known to cause damage to the heart muscle. Some studies suggest that CoQ10 may help to reduce this type of damage mainly due to its antioxidant properties.
One preliminary clinical research trial in children receiving anthracycline chemotherapy demonstrated cardioprotective effects when this supplement was given orally twice daily.
However results from other trials have not shown a significant improvement in cardiac function, overall survival, or heart failure-related death.
Research in this area is limited and conflicting. If you are scheduled for chemotherapy and are interested in taking a CoQ10 supplement, then discuss this with your oncologist before use.
Hypertension (High Blood Pressure)
Several small studies have suggested that CoQ10 may help to lower elevated blood pressure. The UMM notes that it can take as long as 12 weeks to notice any improvements. [3]
In a review of 12 studies, it was concluded that taking this supplement could lower diastolic pressure by an average of 7 mm Hg, and systolic pressure by an average of 11 mm Hg.
Doses between 100 and 120 mg/day were used, and no side effects were reported in any of the 12 studies reviewed. [1, 2, 3]
Larger scale research studies are still needed to determine the therapeutic efficacy of this supplement for hypertension.
UMM warns against attempting to treat hypertension by yourself. It is advised to seek medical advice and assistance for treating any serious condition.
If you are interested in learning more about CoQ10 for blood pressure then speak with your doctor or cardiologist.
Hypercholesterolemia (High Cholesterol Levels)
People with hypercholesterolemia (high cholesterol) commonly have low CoQ10 levels.
Researchers have proposed that supplementing with this compound may have benefits for people with high cholesterol. However, research is currently lacking in this area.
Statin drugs are commonly prescribed to help patients with hypercholesterolemia. While these drugs are effective for this purpose, a growing body of evidence shows these drugs can also cause serious side effects.
According to the Mayo Clinic, some of the possible side effects include:
- Elevated blood-glucose and increased risk of diabetes
- Liver damage, dysfunction and/or disease
- Muscle pain and damage
- Neurological problems like memory loss and confusion [5]
Statin drugs lower CoQ10 levels and taking a supplement may help restore depleted levels. Some clinical evidence suggests that this supplement can reduce the side effects experienced from statin drugs, especially muscle pain. [1]
If you have high cholesterol and are interested in learning more about CoQ10 supplementation, it is best to seek medical advice.
CoQ10 Deficiency
Some diseases are associated with chronic low CoQ10 levels including fibromyalgia, post-myocardial infarction, male infertility, Parkinson’s disease, Peyronie’s disease, migraines, depression and Prader-Willi syndrome. [1]
Supplementation with Coenzyme Q10 to increase levels is commonly recommended for all of the above conditions, but especially in those with fibromyalgia, and when recovering from a heart attack. [1]
Coenzyme Q10 deficiency is rare in humans. Healthy people can produce all they require, and this compound is also found in some food sources. However, therapeutic amounts of CoQ10 may require supplementation to achieve. [1, 2, 3]
Primary Coenzyme Q10 deficiency is a rare genetic disorder that causes defects in biosynthesis of this compound in the body. Supplementation has been shown to improve the neurological and muscular symptoms seen in some patients. [7]
CoQ10 Foods
According to the University of Maryland Medical Center, some of the best dietary sources of CoQ10 are oily fish like sardines, herring, tuna, and salmon. Organ meats, especially beef liver, are also good sources.
Whole grain foods contain lesser, but still appreciable amounts of this coenzyme. [3]
When possible, choose organic vegetables and organic, grass-fed animal foods that are guaranteed to be free of common contaminants like pesticides, antibiotics, steroids, and preservatives.
CoQ10 Supplements
The Natural Medicines Comprehensive Database states that most CoQ10 supplements available in Canada and the US are made in Japan.
Japanese manufacturers most commonly make Coenzyme Q10 from fermented beets and specialized strains of yeast. [1]
Supplements are available in several forms including hard shell capsules, soft gel capsules, tablets, and oral sprays. It is also included in various cosmetic products for topical use.
Most supplements provide between 100-200 mg CoQ10 per dosage. Some supplements will list the source of this ingredient as either ubiquinone or ubiquinol.
Ubiquinone is the oxidized form of this compound that is easily converted to ubiquinol in the body.
Ubiquinol is the reduced form that is found most commonly in the body and is a more expensive supplement ingredient. Both forms are considered equally potent for increasing levels in the body.
The NMCD states that there are currently more than 5700 CoQ10 supplement products available on the market.
Because of the large variety of available products it is important to choose your supplements from reputable manufacturers. When possible look for organically-sourced, contaminant and filler free products.
The UMM notes that Coenzyme Q10 supplements may be better absorbed when taken with a source of healthy fats like those in coconut oil, avocados, and oily nuts and seeds. Taking this product at night before sleeping is also purported to improve its utilization. [3]
CoQ10 levels peak at 5 to 10 hours after administration of oral supplements, and the half-life is roughly 34 hours. [1]
CoQ10 Dosage Guidelines
Proper dosages depend on a variety of factors including age, sex, personal physiology, and the reason for taking this supplement.
It is recommended to always follow dosing instructions on the specific CoQ10 supplement you purchase, unless otherwise instructed by your doctor.
The UMM states that supplements should not generally be used by anyone under the age of 18, except if monitored closely by a qualified medical professional.
Because CoQ10 is a dietary supplement and not a drug, recommended dosages are not set by the FDA.
The NMCD reports the following doses have been used in clinical studies:
- 100 – 200 mg/day doses have been used for statin-induced myopathy (muscle disease)
- 60 mg twice daily doses have been used to decrease risks for future cardiac events
- 100 mg doses, once or twice daily, have been used to improve diabetes markers
- 100 mg/day, divided into 2 or 3 equal doses, has been used for heart failure
- 60 mg twice daily doses have been used for isolated systolic hypertension
- 150 mg/day doses have been used for documented CoQ10 deficiency
- 3 daily 100 mg doses have been used for treating migraine headache
- 160 mg/day has been used for mitochondrial encephalomyopathies
- Twice daily 100 mg doses have been used for pre-eclampsia
- 200 – 300 mg/day doses have been used for male infertility
- 100 mg/day doses have been used for muscular dystrophy
- 50 mg doses three times daily have been used for angina
- 200 mg/day doses have been used for HIV/AIDS [1]
You should discuss the best dosage for your needs with your doctor before starting to take this supplement.
CoQ10 Side Effects
The Natural Medicines Comprehensive Database rates this supplement as Likely Safe when used orally and appropriately.
NMCD states that CoQ10 is generally well-tolerated in healthy adults. There have been no serious adverse effects reported from clinical studies. [1]
Minor gastrointestinal side effects like nausea, vomiting, heartburn, and loss of appetite have been reported, but has been found to occur in less than 1% of patients. [1]
Daily doses in excess of 100 mg should be divided into 2 or 3 equal servings to help minimize side effects. [1]
This coenzyme can interact with certain types of medications including statin drugs, antihypertensive (blood-pressure lowering) drugs, certain chemotherapy agents, and warfarin (coumadin).
It may interact with certain herbs and supplements. Some of these include products with blood pressure-lowering effects such as Andrographis, casein peptides, cat’s claw, fish oil, L-arginine, and theanine.
Interactions may also occur with acacia, beta-carotene, omega-3 fatty acids, red yeast, and vitamins A, C, E and K.
It is recommended that you discuss using CoQ10 supplements with your doctor especially if you have any serious health condition or use any prescription drugs.
- Natural Medicines Comprehensive Database. Coenzyme Q10 Monograph. Accessed Feb. 6, 2017
- Examine. Coenzyme Q10. Accessed Feb. 6, 2017
- University of Maryland Medical Center. Coenzyme Q10. Accessed Feb. 6, 2017
- Brocco, Diana. CoQ10 and Statins: What You Need to Know. October 10, 2016
- Mayo Clinic. Statin side effects: Weigh the benefits and risks. Accessed Feb. 6, 2017
- de Frutos F, Gea A, Hernandez-Estefania R, Rabago G. Prophylactic treatment with coenzyme Q10 in patients undergoing cardiac surgery: could an antioxidant reduce complications? A systematic review and meta-analysis. Interactive Cardiovascular and Thoracic Surgery, Volume 20, Issue 2, 1 February 2015, Pages 254–259.
- Linus Pauling Institute. Coenzyme Q10. Deficiency.