Tuesday, October 3, 2023

Coenzyme Q10: A complete guide

Everything you needed to know about Coenzyme Q10, its health benefits, dosages, food sources, and other important concerns.

Executive Summary

Coenzyme Q10 or CoQ10 helps in energy production inside the body cells and protects them from oxidative damage.

CoQ10 production reduces with age and in many medical conditions. Most of the CoQ10 is produced in the body. Food sources give less than 1% of our daily needs. So CoQ10 supplementation is the only option to raise tissue CoQ10 levels.

A dose of 30 to 100 mg a day of CoQ10 is recommended after 50 years of age for a perfectly healthy individual: 30 mg starting at age 50, progressing to 100 mg after age of 70 years.

CoQ10 has a role in the management of high blood pressure, atherosclerosis, high cholesterol, heart failure, side effects of statin medicines, inflammation, migraines, Alzheimer’s, Parkinson’s, male and female infertility, erectile dysfunction, and chronic fatigue syndrome. It is also useful for anti-ageing benefits as well as endurance athletic performance. The CoQ10 dosages differ in each of these conditions.

Take CoQ10 with meals that contain fats for better absorption. The time of the day does not matter. Read the article for more details.

Disclaimer: The information, including but not limited to, text, graphics, images, and other material, contained on this website is for informational and educational purposes only. No material on this site is intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or another qualified healthcare provider with any questions you may have regarding a medical condition or treatment before undertaking a new healthcare regimen, and never disregard professional medical advice or delay in seeking it because of something you have read on this website.

Coenzyme Q10 or CoQ10 is a compound produced by the body and found in nearly every cell of it. Its main role is in energy production and neutralising destructive compounds in the body called free radicals.

CoQ10 levels reduce with increasing age. They are found to be low in people with certain medical conditions.

While CoQ is present in some foods, its levels are low enough that eating those foods doesn’t make much difference to the body levels of CoQ10. As a result, CoQ10 supplementation is widely studied for healthy living, disease prevention, and treatment.

What is CoQ10?

Coenzyme Q10 is a fat-soluble molecule from the ubiquinone family of compounds. It is synthesized by all animals including humans. Perhaps, this ubiquitous nature gives the family its name.😎

In our body, it is available in two forms: Ubiquinol and Ubiquinone, with the former being 90% of the CoQ10 in the body. While these forms are interchangeable inside the body, ubiquinol is more relevant as it is the one with antioxidant properties. It is also the form that is better absorbed. However, when we refer to CoQ10, we are talking about both the forms together.

While CoQ10 is present everywhere in the body, it is found mainly in the organs that have the highest energy demands. In the descending order of concentration, they are the heart, skeletal muscles, liver, kidneys, intestines, lungs, and brain. Consequently, depletion or deficiency of CoQ10 hampers the functions of these organs more. CoQ10 supplementation helps in some disorders of these organs.

Our body produces the highest amount of CoQ10 around the age of 25 years. After that, its production starts falling at different rates in various organs. For example, in the heart tissue, the CoQ10 production at the age of 65 years is about half of that at the age of 25 years.

Functions of CoQ10

The main functions of CoQ10 are to help energy production inside the body cells and protect them from oxidative damage.

Energy Production

Our cells use a chemical called ATP as fuel for their energy needs. Do you really need the full form of ATP? It is Adenosine triphosphate.🤪

ATP is produced from carbohydrates and fats with CoQ10 acting as a catalyst. This process takes place inside each cell in its part called mitochondria. So CoQ10 is found in almost all cell mitochondrial membranes.

With age, the production of CoQ10 in our organs falls. So they are not able to generate enough energy to function properly. This necessitates CoQ10 supplementation as we age beyond 50 years.

In certain medical conditions, CoQ10 levels are low. While CoQ10 may not cause those problems, it is quite conceivable that an organ with sufficient CoQ10 levels is able to resist the disease progression. But when those levels are low, the cells of that organ are unable to produce enough energy for its functioning and protect against further damage. So when such medical disorders are noticed, low CoQ10 levels are observed, too.

Antioxidant Activity

The process of energy production also generates molecules called free radicals. These are destructive particles, which can wreak havoc inside the body. They can alter cell DNA, break cell membranes and possibly cause cell death. All of these can lead to degenerative disorders such as cancer or dementia. The process of generation of free radicals is called oxidative stress and is considered as the main cause of ageing of an organ.

CoQ10 neutralises free radicals, especially those that are produced in the process of cellular energy generation. This is called an antioxidant activity and CoQ10 is said to be an antioxidant.

Cell membranes are made up of fats and CoQ10 is a fat-soluble molecule. So CoQ10 is found in all cell membranes. CoQ10 reduces oxidative stress that develops in cell membranes due to energy production activity.

CoQ10 also recycles or regenerates certain other antioxidants such as vitamin E.

In each cell that produces energy, the antioxidant role of CoQ10 becomes vital when its levels start dropping in the body due to age or other medical conditions.

With age, CoQ10 levels fall in the organs leading to reduced antioxidant activities. This can set in degenerative disorders of those organs.

In certain medical conditions, CoQ10 levels are found to be low. In the corresponding organs, oxidative stress increases as a result, causing DNA modifications as well as cell death. So low CoQ10 levels may be causing those conditions by inhibiting the protective antioxidant mechanisms.

Daily Requirements of CoQ10

Our body has about 2 g of CoQ10. This amount keeps getting utilised every four days or so. As a result, our body needs 500 mg of fresh supply of CoQ10 daily. Very little—just about 5 mg—of this is obtained from our diet. The rest is produced in the body.

So in general, there is no daily requirement of external CoQ10. Only when the body’s levels of CoQ10 are depleted due to age or certain medical conditions does one need to think of daily intake of CoQ10.

Sources of CoQ10

Dietary sources of CoQ10 are organ meats, fish, eggs, and dairy. However, the amount one can get from them is really minuscule. Considering that just about 1% of your daily requirement comes from food sources, it might not be worth looking at them for covering CoQ10 deficiency, if any.

Don’t believe it? Here is a brief reckoner for you:

  • A typical serving (85 g or 3 oz) of beef or pork (some of the best sources of CoQ10) will give you 3 mg of CoQ10;
  • A similar portion of chicken will give you 1 mg of CoQ10;
  • A large egg will give 0.1 mg of CoQ10;
  • A serving of peanuts or pistachios (28 g or 1 oz) will give you 0.5 mg of CoQ10.

Now, let me know how you will get, say, 100 mg (one-fifth of your daily need) a day through foods, without eating copious amounts of unhealthy organ meats. For reference: 11 Foods High In Coenzyme Q10 (CoQ10) That You Can Tank Up On.

Supplemental CoQ10 is the best option if one suspects CoQ10 deficiency. Take a ubiquinol supplement if possible, instead of a ubiquinone one as the former has better absorption in the body.

Consume your CoQ10 supplement with fats to increase its absorption. Some companies provide their CoQ10 supplement in an oily soft gel form, for the same reason. Otherwise, one can simply take CoQ10 supplements with a meal that contains some fat. It does not matter what time time of the day you take your supplement.

Upper Limit on CoQ10 Intake

There are no established toxic levels of CoQ10. In general, one is suggested not to exceed 1,200 mg of CoQ10 a day. However, some clinical trials have used 3,000 mg a day of CoQ10 without any problems.

Only about 5% of the CoQ10 consumed as a supplement reaches the blood. So high doses don’t really give CoQ10 overload to the body.

After 2,400 mg a day, additional CoQ10 intake does not seem to increase blood levels of CoQ10. So one can consider that as the upper intake limit.

CoQ10 can reduce the efficacy of blood thinners such as warfarin. Consult your doctor before taking CoQ10 if you are taking warfarin.

Doses ranging from 30 mg to 500 mg of CoQ10 a day have been used in most clinical trials. If you wish to exceed 500 mg a day, even if you are otherwise healthy, you should consult a medical doctor first.

Benefits of CoQ10 Supplementation

As is the case with most nutrients, the evidence about the use of CoQ10 in different medical conditions is not rigorously tested. Many small trials have shown benefits, while some have failed to show statistically significant improvement. But that is the nature of the supplementation trials. Read on this website: How to understand the evidence from clinical trials of nutrients. This comprehensive article of mine will tell all that you need to know before jumping to conclusions about nutrient trials.

I went through the abstracts and conclusions of hundreds of medical papers before writing this article. Each had a different dosage of CoQ10, duration of use, and number of patients treated. Some involved adding CoQ10 to the existing treatment. Some were studies done on animals similar to humans, and some others were in vitro or studies done in lab petridishes. Some papers were on young people looking for prevention, while others were for ageing patients with poor health. Some trials involved patients with co-morbidities (other medical conditions). Some checked for changes in blood levels; some others looked for reduction in symptoms; and few others looked for cure.

A few trials showed clear benefits, some others showed benefits that were not statistically significant (that means, there was a 5% probability that an outcome implying a benefit was seen just by chance but actually there was no such real benefit). Some trials showed evidence conflicting with the earlier, similar trials.

To find a way out of such confusion, I will mention about the benefits of CoQ10 that are accepted by experts, as well as those that are logically expected. I will also give the reasoning behind the same.

I will highlight the trials that found a benefit and will ignore those that did not see such a benefit. That would not be a biased selection though.

If you are looking for black swans and you did not find them, that does not conclusively prove that black swans don’t exist. It is better to look at photos posted by someone else who found such swans and not highlight the images of empty lakes posted by others. With these disclaimers, you are welcome to take your call on whether to proceed with CoQ10 supplementation based on that kind of evidence.

In my view, this lack of clarity will go on for a few more decades till we see more conclusive evidence either way. In the absence of that, you have to decide on the use of CoQ10 for your health needs. The two sides of the argument are “what is the harm?” versus “why experiment?”.

I will break the benefits of CoQ10 supplementation into three groups:

  1. General health,
  2. Disease prevention, and
  3. Disease treatment.

I will leave out discussing the role of CoQ10 in conditions where a non-medical person can not have any input on CoQ10 use, viz. after a heart attack or for heart damage caused by chemotherapy.

General Health


CoQ10 is protective against free radical damage that causes body degeneration. Since the internal production of CoQ10 drops with age, it is a good idea to supplement with CoQ10 after the age of 50 years. Use 30 to 100 mg of CoQ10 a day.

Athletic Performance


  • Improves strength in older people;
  • Reduces oxidative stress caused by aerobic exercises;
  • Reduces fatigue in endurance activities. CoQ10 stabilises the skeletal muscle cell membranes, which reduces the fatigue. If you are an endurance athlete, you may wish to consider this.

300 mg a day of CoQ10 was found to give above benefits; 100 mg a day did not help much.

Disease Prevention

Atherosclerosis or Plaque Buildup in Arteries

Oxidation of low-density lipoproteins (LDL) is considered to be an early step toward plaque buildup in the arteries. CoQ10 is found to prevent that when taken in very high doses. Since you and I cannot take such high doses, consider taking 100 to 300 mg a day, which may benefit to some extent.

Some immune cells called monocytes lead to adhesions in the blood vessel walls causing plaque buildup. Taking 200 mg a day of CoQ10 for 10 weeks was shown to prevent adhesions, potentially avoiding plaque formation.

High Cholesterol

Lipoprotein A or Lp(a) is a really bad, sticky type of cholesterol. It is even worse than LDL for heart health. High levels of Lp(a) raise the risk of heart disease. 100 to 300 mg of CoQ10 a day lowers high Lp(a) levels.

Disease Treatment

Congestive Heart Failure

Now, this is one condition where you are not supposed to have any treatment view if you are not a medical doctor. So take this information just for the sake of knowledge.

CoQ10 improves symptoms of congestive heart failure (CHF). CHF is caused when the heart is not able to pump enough blood to offset damage due to oxidative stress in the arteries (Coronary Artery Disease) or high blood pressure. Take 300 mg a day.

High Blood Pressure

High blood pressure or hypertension is caused when a compound called nitric oxide does not adequately act on the inner linings of the blood vessels. The antioxidant action of CoQ10 is thought to reinstate this nitric oxide action and help reduce blood pressure. Some small trials have shown this benefit of CoQ10 for high blood pressure.

Keep in mind that you should not rely on only CoQ10 for controlling high blood pressure. Seek medical help and take proper medicines. Use CoQ10 as supportive treatment.


Chronic, low-grade inflammation in the body is the main cause of many lifestyle disorders, such as heart disease.

Certain blood chemicals are the markers for inflammation, viz. c-reactive protein (CRP), interleukin-6 (IL-6), and tumour-necrosis factor-alpha (TNF-α). A marker means ‘a chemical that indicates something’.

Clinical trials have shown that CoQ10 significantly lowers these inflammatory markers.

Side Effects of Statins

Statins are cholesterol-lowering medicines. They lower blood cholesterol by preventing the action of an enzyme called HMG-CoA reductase. Unfortunately, exactly the same enzyme is also needed in the production of CoQ10 in the body. So when statins lower cholesterol, they also lower CoQ10 in the body. Such a body is vulnerable to all the CoQ10 deficiency problems that we are discussing in this article.

Taking 100 mg CoQ10 a day with statins is found to reduce symptoms of statin-related muscle pain and weakness.

Taking CoQ10 along with statins is found to increase high-density lipoproteins (HDL).


Diabetes involves improper energy metabolism. It also causes excess oxidative stress. People with diabetes are found to have lower blood levels of CoQ10 than normal people.

A hormone called insulin helps body cells utilise blood glucose. If the cells become resistant to this action of insulin, the body cannot use blood glucose properly, raising its levels. A person develops such insulin resistance even before the onset of diabetes.

While the exact mechanism is not known, abnormal mitochondrial functioning is noticed in insulin resistance. CoQ10 protects mitochondria and lowers insulin resistance. So it is thought to help prevent diabetes.

High blood sugar in diabetes can cause oxidative stress and nerve damage. This is called diabetic neuropathy. CoQ10 is protective against diabetic retinopathy.

CoQ10 helps in protection against high blood pressure and arterial plaque formation (atherosclerosis) in diabetic patients.

For a detailed discussion, read on this website: Supplements for type 2 diabetes.

Parkinson’s Disease

Loss of a neurotransmitter called dopamine in brain neurons is a feature of Parkinson’s disease. CoQ10 prevents the loss of dopamine neurons.

The small clinical trials involved in this testing had used between 300 to 3,000 mg of CoQ10 a day. The levels in excess of 500 mg a day are not practical to be managed without medical supervision.

For a comprehensive discussion, read on this website: Supplements for Parkinson’s disease.

Alzheimer’s Disease

Alzheimer’s is the most common form of memory loss or dementia. Oxidative stress is considered to be an important factor in its development. Since CoQ10 helps in preventing such oxidative excess, it is being evaluated for the management of Alzheimer’s.

Some animal studies have shown the benefit of CoQ10 on the markers of Alzheimer’s. CoQ10 slows the production of beta-amyloid, which are proteins that build up in the brains of people with Alzheimer’s. But people with Alzheimer’s don’t have low levels of CoQ10.


One of the causes of migraines is excess inflammation and free radical generation in certain brain cells. CoQ10:

  • May help prevent migraines;
  • Reduces frequency and severity of episodic headaches;
  • Reduces duration and frequency of migraines.

Take 150 to 300 mg of CoQ10 a day.


Depression is highly correlated with oxidative stress. Depressed people seem to have low levels of CoQ10.

Male Fertility

CoQ10 protects male semen from oxidative damage. This helps improve sperm quality and quantity and reduce male infertility. Take 200 mg a day.

Female Infertility

With advancing age, the reduced production of CoQ10 in a female body leads to oxidative damage to eggs, reducing their quality. CoQ10 can help protect against this loss. Older women of reproductive age should consider CoQ10 supplementation for healthier conception.

Erectile Dysfunction

Oxidative stress has been linked to the progression of erectile dysfunction. CoQ10 protects against this damage, increases activity of antioxidant enzymes, and improves erectile function. Take 200 mg a day.

Chronic Fatigue Syndrome

People with chronic fatigue syndrome have low levels of CoQ10. Seventy percent of people who tried CoQ10 supplementation for unexplained chronic fatigue found benefits.

My Views

Most of the trials about CoQ10 supplementation in various medical conditions have conclusions all over the place. But these are a few common messages one can take from them:

  1. CoQ10 does not cause any harm even in high doses;
  2. CoQ10 helps multiple systems of the body;
  3. CoQ10 supplementation is more relevant as you age;
  4. When you take CoQ10 for a condition, the rest of your body systems also benefit from taking it;
  5. There are no perfect doses for CoQ10 for any medical condition. We just know the doses that were used by researchers in the trials that worked;
  6. CoQ10 is a natural part of your body. So taking it won’t introduce any extraneous substance inside the body;
  7. The conventional option of trying to get CoQ10 through foods won’t work because most foods have negligible amounts of CoQ10. Plus, the foods that are high on CoQ10 are quite unhealthy otherwise (organ meats).

In my view, it makes absolute sense to take 30 to 100 mg of CoQ10 a day as a protective and preventive option once you cross the age of 50 years. Start with 30 mg a day when you reach 50 years of age. Progressively increase it to 100 mg a day as you touch and cross the age of 70 years.

To Read More

Articles in Nutrients Series

  1. Omega–3 Oils: A Complete Guide
  2. Vitamin D: A Complete Guide
  3. Vitamin A: A Complete Guide
  4. Coenzyme Q10: A Complete Guide
  5. Turmeric (Curcumin): A Complete Guide
  6. Lutein: A Complete Guide

Articles in Supplementation Series

  1. Why Do We Need Supplements?
  2. Supplements for Various Age Groups
  3. Supplements for Preventing Ageing & Age-Related Diseases
  4. Supplements for Type 2 Diabetes
  5. Supplements for Osteoarthritis
  6. Supplements for Hair Loss
  7. Supplements for Fatty Liver
  8. Supplements for Autoimmune Disorders
  9. Supplements for Anemia
  10. Supplements for Prostate Enlargement
  11. Supplements for Macular Degeneration
  12. Supplements for PCOS
  13. Supplements for Parkinson’s Disease
  14. Supplements for Gout
  15. Supplements for Eczema

First published on: 5th May 2022
Image credit: Polina Tankilevitch from Pexels
Last updated on: 3rd June 2022


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