Coenzyme Q10 / Ubiquinol / Ubiquinone

Coenzyme Q10 / Ubiquinol / Ubiquinone
What is Coenzyme Q10?
Ubiquinol vs ubiquinone – what’s the difference?
Where does coenzyme Q10 / ubiquinol come from?
What does coenzyme Q10 (ubiquinol / ubiquinone) do?
Coenzyme Q10 levels
CoQ10 supplementation
What are Coenzyme Q10 (ubiquinone and ubiquinol) supplements used for?
Ubiquinol for coenzyme Q10 deficiency
Mitochondrial myopathies and CoQ10
CoQ10 for migraines
Coenzyme Q10 for diabetes
Ubiquinol for fertility
CoQ10 for heart failure
CoQ10 for Angina & cardiomyopathy
CoQ10 for high blood pressure
Coenzyme Q10 for those on beta blockers
Coenzyme Q10 for those on statins
CoQ10 for those undergoing cancer treatment
Coenzyme Q10 for Parkinson's disease
CoQ10 for Huntington's disease
CoQ10 to enhance physical performance
CoQ10 to treat gum disease
Coenzyme Q10 for weight loss
When it comes to supplementation which is better ubiquinol or ubiquinone (CoQ10)?
Issues with bioavailability and how to choose a product
Coenzyme Q10 Dosage
Coenzyme Q10 safety
Conzyme Q10 / Ubiquinone / Ubiquinol side effects
Coenzyme Q10 Precautions and Warnings

What is coenzyme Q10?

Coenzyme Q10, also referred to as CoQ10, ubiquinol, ubiquinone or ubidecarenone is fat-soluble vitamin-like nutrient. It is found in most animal and human cells and is highly concentrated the organs and tissues1. It is so prolific that the names ubiquinol and ubiquinone are, in fact, derived from the word 'ubiquitous' - meaning ‘present everywhere’.

Ubiquinol vs ubiquinone – what's the difference?

Ubiquinol and ubiquinone are two related but chemically different forms of Coenzyme Q10, both of which play important roles within the body. The main difference between them is determined by their chemical state in a biological process known as an oxidation-reduction or ‘redox’ reaction.

The body’s cells continually undergo redox reactions to maintain a state of balance in various chemical compounds for optimal cellular function. Imbalances in cellular redox reactions are attributed to the development of several diseases. As such, maintaining a balance in these reactions is vital for optimal health.

During the redox reaction, reduction occurs when oxidised CoQ10 (aka ubiquinone) is used by the body and reduced, which causes it to:

  • Gain electrons
  • Gain hydrogen

This transforms ubiquinone to ubiquinol (the reduced form)

When oxidation occurs, reduced CoQ10 or ubiquinol:

  • Loses electrons
  • Loses hydrogen

This transforms ubiquinol to ubiquinone (the oxidised state).

If there are insufficient levels of ubiquinol in the body, it will reduce ubiquinone to form ubiquinol, and vice versa. In healthy individuals, approximately 95% of the CoQ10 circulating in plasma is in the reduced form, ubiquinol.

 What is the difference between ubiquinol and ubiquinone

Where does coenzyme Q10 / ubiquinol come from?

Coenzyme Q10 is primarily made by the body in a process known as biosynthesis. Small amounts may also be obtained from the diet.


Coenzyme Q10 is synthesised in the liver. In order for the liver to produce CoQ10, the body has to be well-nourished. CoQ10 is made from the amino acids, tyrosine and phenylalanine. Its production involves a multi-cascade of events that requires at least 7 vitamins - B6, Folate, C, B2, B3, B12, Pantothenic acid - as well as trace minerals such as magnesium and selenium. Deficiencies in these vitamins and minerals can compromise CoQ10 production.

Dietary sources of coenzyme Q10 - ubiquinol

Dietary sources of Coenzyme Q10 (CoQ10)

Coenzyme Q10 can be obtained in the form of ubiquinone through dietary means, although this is limited.

  • Organ meat (heart, liver, kidney, testes, thymus)
  • Red meat
  • Seafood (sardines, mackerel)
  • Certain nut oils (peanut, soy)
  • Dark vegetables (spinach, broccoli)
  • Legumes
  • Nuts (almonds, peanuts)

The average diet is estimated to provide approximately 10mg of ubiquinone per day.

What does coenzyme Q10 (ubiquinol / ubiquinone) do?

Coenzyme Q10 has two important functions in the body4:

1. Aiding in energy production

Coenzyme Q10 is found within the membranes of mitochondria. Mitochondria are small rod-shaped organelles found within the body's cells. They act as ‘power generators’ converting oxygen and nutrients into adenosine triphosphate (ATP) during a metabolic process known as cellular respiration. ATP is a complex organic chemical that gives cells the energy they need to function and coenzyme Q10 in the form of ubiquinone is vital to this process. It is therefore essential in maintaining good health in humans.

When low levels of CoQ10 are present within the mitochondrial membranes, we have issues with this form of energy production which can cause a variety of metabolic diseases.

2. Acting as an antioxidant

Cellular respiration in our bodies produces heat and oxidation (a chemical process that produces free radicals as a by-product). Free radicals are unstable atoms that can cause oxidative stress in the body.

Oxidative stress refers to an imbalance in the production of free radicals (think of these as ‘waste products’) and the body’s ability to neutralise these with its natural antioxidant defences (think of these as the clean-up crew that manages the waste products).

When the body is unable to neutralise and detoxify itself of the excess free radicals, these overwhelm the system and oxidative stress occurs. Oxidative stress can cause chronic inflammation, damage to cell membranes, changes in DNA and even cell death, all of which may lead to the development of illness and disease5.

Ubiquinol is the active form of Coenzyme Q10 that plays a vital role in the process of antioxidant protection. It helps to prevent oxidation and thus protects the body from excess free-radical production and the resulting inflammation and damage that leads to disease.

Interestingly, coenzyme Q10 is the only antioxidant that can self-regenerate and it is also involved in the regeneration of other antioxidants.

Coenzyme Q10 levels

Healthy levels of CoQ10 are considered to be 0.8–1.2 mg/L in human plasma6. Despite the body’s ability to synthesise Coenzyme Q10 naturally, tissue levels generally peak around the ages of 20 to 30 and decline thereafter. The conversion of ubiquinone to ubiquinol also declines with age.

Low levels of CoQ10 may also occur due to:

  • Oxidative stress as a result of the natural ageing process. This causes an imbalance in free radicals and antioxidants in the body. Due to the fact that CoQ10 is not available to act as an antioxidant to neutralise the free radicals, these remain unchecked and may cause chronic inflammation and aging-related cell and tissue damage which can, in turn, influence the development of metabolic conditions and disease.
  • Nutritional deficiencies in the vitamins and minerals required to synthesise ubiquinol – particularly vitamin B6.
  • Lifestyle choices such as smoking
  • Genetic defects that affect the way CoQ10 is synthesized or used by the body
  • Mitochondrial disease
  • Taking certain medications, such as7:
    • Beta-blockers (blood pressure medications – these include atenolol (Tenormin), labetolol (Normodyne), metoprolol (Lopressor or Toprol), and propranolol (Inderal))
    • Fibric acid derivatives for cholesterol
    • HMG Co-A reductase inhibitors (statins – these include atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol, and simvastatin (Zocor))
    • Tricyclic antidepressant medications (these include amitriptyline (Elavil), doxepin (Sinequan), and imipramine (Tofranil).

Low levels of CoQ10 have been associated with8:

CoQ10 supplementation

When it comes to supplements, Coenzyme Q10 is available in its two major forms:

  1. Ubiquinone (also marketed as CoQ10)
  2. Ubiquinol

Common names include:

  • CoQ10
  • Ubiquinol
  • Ubiquinol QH
  • Advanced CoQ10
  • Mega CoQ10
  • QH-absorb
  • Ultra CoQ10


What are Coenzyme Q10 (ubiquinone and ubiquinol) supplements used for?

In supplement form Coenzyme Q10 (ubiquinol / ubiquinone) may help to improve cellular health and protect the body’s cells from oxidative stress and chronic inflammation which can cause damage and lead to the development of disease.

While this means that these CoQ10 supplements may have a number of health applications, at present research is limited and some findings remain inconclusive. This does not mean that there is no value in the studies that have been conducted, but rather that further, better designed and controlled large-scale trials are required to conclusively prove or disprove many of the health benefit claims in circulation.

In many instances, CoQ10 is regarded as an important coadjuvant (i.e. a supplement that enhances the primary medication or therapy) in the treatment of disease, especially in the elderly.

In addition, due to the fact that it is regarded as being safe to take with few adverse side effects, it can generally be taken by adults without causing any harm. So much like vitamins, many people take it ‘just in case’ it can help a particular health issue or condition.

Here we’ll look at what scientific research shows with regard to the benefits of CoQ10 supplementation as well as areas that require further investigation to provide scientific evidence that justifies its use.

Ubiquinol for coenzyme Q10 deficiency

While rare, some people (less than 1 in 100,000) suffer from primary coenzyme Q10 deficiency as a result of a genetic disorder that prevents their body from making CoQ109. This can cause a number of neurological (nerves and nervous system) and muscle-related issues.

In others, the body may produce adequate amounts of CoQ10, but these levels are reduced due to mitochondrial respiratory chain (MRC) disorders, resulting in a condition known as secondary Coenzyme Q10 deficiency10.

Coenzyme Q10 deficiency may cause11,12:

  • Cerebellar ataxia (A degenerative neurological condition that results from damage to the cerebellum - the part of the brain responsible for receiving sensory information from the body and controlling physical movement)
  • Nephropathy (a disease of the kidneys)
  • Isolated myopathy (a condition in which the muscle fibres do not function properly in one area)
  • Encephalomyopathy (brain dysfunction combined with muscle weakness)
  • Severe infantile multisystem disease (a condition that affects numerous bodily systems and may cause organ failure and death in infants)

While sufferers of both primary and secondary CoQ10 deficiency may respond to ubiquinone or ubiquinol supplementation, this is not universal. High doses of CoQ10 may improve muscle function in some and can also be life-saving for some infants suffering from brain disorders accompanied by muscle weakness (encephalomyopathy)13, 14, 15.

Mitochondrial myopathies and CoQ10

The term ‘mitochondrial myopathies’ refers to a group of neuromuscular diseases (i.e. diseases that involve the skeletal muscle and nervous system) that develop as a result of damage to the mitochondria (the structures within cells that aid in energy production to power the body).

This dysfunction of the mitochondria may cause:

  • Ophthalmoplegia (weakness or paralysis of the eye muscles)
  • Isolated muscle disease with or without with or without exercise intolerance and/ormuscle pain (myalgia)
  • Severe disease of the muscles
  • Brain disease, disorder, or damage accompanied with muscle weakness (encephalomyopathy) in infancy and childhood
  • MELAS - mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes

CoQ10 has been used to treat those suffering from mitochondrial disorders in cases where deficiencies are noted as well as when levels are unknown and even when they are not reduced. While the evidence from clinical trials is limited, because of the modest benefits demonstrated in some small trials16 and because of the lack of evidence of serious side effects, CoQ10 is often recommended for those suffering from these types of diseases.

It is thought that CoQ10’s antioxidant properties may help to alleviate the oxidative stress (i.e. a condition caused by an imbalance in the production of damaging free radicals and the body’s ability to neutralise these) that these types of disorders cause in the body, and in turn, improve muscle function.

UbiQGel (a specific coenzyme Q10 formation) has been given FDA approval for mitochondrial encephalomyopathies, including MELAS, Kearns-Sayre syndrome, and MERRF (myoclonus epilepsy with ragged red fibres)17. For those considering ubiquinol supplementation for these disorders, it is important to note that in the studies conducted to gain this approval, it took 6 months of supplementation for participants to see effective results.

CoQ10 for migraines

Due to the potential role of mitochondrial dysfunction in the development of migraines, ubiquinol has been used to treat these types of headaches. One study even showed that volunteers who were treated with Coenzyme Q10 in doses of 100mg three times per day experienced more than a 50% reduction in migraine attacks after three months than the control group18.

While larger trials are necessary to confirm CoQ10’s benefits in migraine prevention are required, the preliminary evidence is promising. Both the American Headache Society19 and American Academy of Neurology20 mention it’s potential in this regard.

Coenzyme Q10 for diabetes

Diabetes mellitus is associated with oxidative stress and impaired energy metabolism. Coenzyme Q10 levels have been found to be lower in diabetics than in healthy individuals.

Due to its antioxidant properties which help to prevent oxidative stress, CoQ10 supplementation has been proposed in the treatment of diabetes.

The findings of various studies on its benefits are mixed. Some studies claim that it claim that it may assist glycaemic (blood sugar level) control, decrease triglycerides, and improve high-density lipoprotein (HDL) cholesterol in type 2 diabetes sufferers21. Others have found that it has little benefit. Although these differences may be due to differences in the quality and bioavailability of the products being used in the various trials22.

The development of type 2 diabetes involves the early onset of glucose intolerance and high levels of insulin circulating in the blood relative to the level of glucose (this is referred to as hyperinsulinemia) due to the progressive loss of tissue responsiveness to insulin. Recent studies show a link between insulin resistance and low levels of CoQ10 and demonstrate that Coenzyme Q10 supplementation may help to restore insulin sensitivity23. This evidence suggests that CoQ10 supplementation in individuals with prediabetes may be more useful to prevent type 2 diabetes than to treat and manage it.

More research is required and is being funded by various diabetes research and education groups.

Ubiquinol for fertility

Ubiquinol for male fertility

Difficulties in conception and the inability to have children affects 10 to 15 percent of couples across the globe. Issues related to the male partner account for up to half of infertility cases, and 25 to 87 percent of these are due to male subfertility24 (i.e. men displaying reduced fertility25). The reason for this is considered to be oxidative stress.

CoQ10 levels in seminal fluid is considered an important biomarker of healthy sperm. Studies show that in men, supplementation with ubiquinol has a significant effect on improving sperm-related issues such as26,27:

  • Low sperm count
  • Low motility (i.e. poor sperm movement)
  • Abnormal sperm shape

This has been attributed to CoQ10’s ability to reduce oxidative stress and the resultant damage to cells. While it is obvious that healthy sperm is necessary to optimise the chances of successful pregnancies and live births, just how effectively the results of ubiquinol’s influence of sperm translate into pregnancy rates and live births has been significantly less studied.

At present low quality evidence from a small number of trials suggests that ubiquinol supplementation in subfertile men may increase the rates of pregnancy and live birth rates experienced in couples attending fertility clinics. However, for conclusive evidence to be produced, better designed trials that examine the exact role of antioxidants in improving pregnancy and live birth rates are required28.

Ubiquinol for female fertility

Egg production, quality and ovulation all play vital roles in successful conceptions, pregnancies and live births. It is a well-known fact that reproductive success declines with age.

A woman’s eggs (oocytes) are cells and the mitochondria within them are responsible for the cell’s energy production. The maturation of eggs, cell division in the embryonic stage, embryo development and implantation in the uterus, all depend on large supplies of energy from these mitochondria. As such, human egg cells contain more mitochondria than any other cells and they depend on CoQ10 for energy production.

Researchers have speculated that declining levels of CoQ10 after the age of 30 may be the reason why women’s eggs are far less efficient in energy production after this age29. In addition, lower levels of CoQ10 which leads to reduced energy production and increased oxidative stress may also adversely impact ovulation, which requires a significant amount of cellular energy to take place30. Both of which make viable pregnancies more difficult after the age of 30.

For these reasons it has been speculated that ubiquinol supplementation may help to fend off oxidative stress and improve mitochondrial function in subfertile women (i.e. women showing reduced fertility). This may, in turn, help to reverse the declines in energy production, improve egg quality and help to ensure successful ovulation, development and implantation.

To date there have been few human trials examining the effects of CoQ10 on female fertility. The majority of the research done to date has also focussed on CoQ10 supplementation in women undergoing intrauterine insemination (IUI) or in vitro fertilisation (IVF) for infertility instead of its role in natural pregnancy.

That said, the evidence that does exist in terms of exactly how CoQ10 impacts female fertility when it comes to actual pregnancies and live births does show modest improvements in these statistics but is generally regarded as being of low quality. Further, more comprehensive trials are therefore required to draw conclusive results.

CoQ10 for heart failure

It is believed that oxidative stress plays a role in the development of heart failure. This is supported by the fact that heart biopsies from those with heart failure often show depleted CoQ10 levels.

Existing clinical data shows some evidence that supplementation with this powerful antioxidant may be beneficial to those suffering from congestive heart failure (CHF)31. It is, however, widely accepted that further research is required in order to establish the long-term safety and efficacy of this type of therapy.

As it currently stands, CoQ10 is used as an adjuvant therapy (i.e. a supplement that enhances the effectiveness of other heart failure drugs) by cardiologists but is not recommended as a first-line or stand-alone therapy to treat congestive heart failure32.

CoQ10 for Angina & cardiomyopathy

While it has been suggested that CoQ10 supplementation may be beneficial in those suffering from angina, cardiomyopathy and cardiovascular disease in general, to date there has not been enough scientific evidence to conclusively prove this. Further, longer-term trials are required to determine its effects.

CoQ10 for high blood pressure

It is a well-known fact that unmanaged high blood pressure increases the risk of cardiovascular events such as heart attacks and strokes. Some evidence shows that CoQ10 improves blood vessel function and lowers blood pressure in 55% of the patients who take it. As such, it is believed that it could be beneficial to those with high blood pressure (hypertension) in not only lowering blood pressure but also in aiding to reduce blood pressure medication dosages and even as a natural alternative to these.

Based on existing research, however, there is currently no reliable scientific evidence to conclusively support these claims or justify ubiquinol use as a stand-alone high blood pressure treatment33.

Coenzyme Q10 for those on beta blockers

CoQ10 for those on beta blockers

Some beta blockers (a type of blood pressure medications) like propranolol and metoprolol block the biological pathway of coenzyme Q10-dependent enzymes in the body34.  As such, it is often suggested that it may be beneficial for those taking these types of medications to supplement with CoQ10. There is, however, no evidence that beta blockers cause clinically significant reductions of Coenzyme Q10, and as such, there is currently no indication to supplement when taking these35.

In addition, those currently on medication for high blood pressure should be aware of the fact that CoQ10 supplements may further, albeit slightly, lower blood pressure. While this may help to reduce dosages of certain blood pressure medications, in some instances where blood pressure is adequately managed with medications, this may cause unwanted side effects. It is therefore important to discuss CoQ10 supplementation with your treating doctor before starting supplementation or adjusting your existing blood pressure medication.

Coenzyme Q10 for those on statins

Certain cholesterol-lowering medications known as statins may reduce the natural production of CoQ10 (ubiquinone), which plays a vital role in the production of muscle cell energy in the body. Researchers have speculated that lower levels of ubiquinone in the muscles as a result of statin use may contribute to muscle weakness and injury36.

It has therefore been suggested that CoQ10 supplementation with ubiquinone or ubiquinol could help to reduce the muscle weakness that develops as a result of taking these types of medications. The outcomes of various clinical trials have, however, been contradictory. As such, no definitive scientific conclusions can be drawn as to whether or not those on statins should be taking CoQ10 and further trials are required to do so.

Nevertheless, because no serious adverse side effects of ubiquinol and ubiquinone supplements have been reported, these may be considered. It is best to consult the doctor prescribing statins in this regard.

CoQ10 for those undergoing cancer treatment

No relevant clinical trials have been conducted on CoQ10 in the treatment of cancer37.

A great deal of alternative and complementary medicine information promotes the use of CoQ10 for cancer patients undergoing chemotherapy. This is based on the suggestion that it may increase the tolerance to this form of cancer treatment and the associated treatment-related fatigue that is often experienced, while also protecting the heart.

While supplementation with coenzyme Q10 leads to increased plasma levels thereof, there is not sufficient clinical evidence to support its fatigue-fight effects in those undergoing cancer treatment38. To date, the studies investigating the heart-protecting effect of CoQ10 in patients undergoing anthracycline therapy have been flawed and no definite conclusions can be drawn as a result.

Some studies show that CoQ10 has the ability to stimulate the immune system in both animals and humans with and without cancer. For this reason, it may be used by those undergoing cancer treatment37.

It is important to note that CoQ10 may reduce the effectiveness of Warfarin therapy in those taking this medication to lower their risk of cancer-related venous thromboembolism (clots in the deep veins). In addition, in some individuals CoQ10 may exacerbate the side effects of chemotherapy such as vomiting and diarrhoea.

There is also some concern that antioxidants may interfere with certain chemotherapy medications, making them less effective, although to date no conclusive evidence has been found. Nevertheless, always speak to your oncologist before starting any new supplement while undergoing chemotherapy.

Coenzyme Q10 for Parkinson's disease

Primary research showed that mitochondrial dysfunction plays a role in the development of Parkinson’s disease. This stimulated interest in whether low levels of coenzyme Q10 could predispose certain people to its development and whether high dose supplementation (1200mg per day) with ubiquinol or ubiquinone could improve cellular respiration and prevent oxidation enough to protect nerve cells (neurons) from damage, thus slowing or preventing the progression of Parkinson’s disease.

The available evidence, however, suggests that CoQ10 has no neuroprotective effect or symptomatic benefit for Parkinson’s sufferers39,40,41.

CoQ10 for Huntington's disease

To date research has shown no evidence that coenzyme Q10 slows the progression of Huntington’s disease, at least in the early stages. In 2014, the largest randomized, controlled trial (i.e. the ‘gold standard’ in clinical trials) ever conducted on Huntington’s disease, the 2CARE trial, was halted due to futility. Researchers concluded that CoQ10 supplementation was not a justified treatment to slow the progression of the disease42.

CoQ10 to enhance physical performance

Due to the fact that Coenzyme Q10 is involved in cellular energy production and acts as a powerful antioxidant, reducing oxidative stress, it has been suggested that supplementation with ubiquinol or ubiquinone may increase physical performance and reduce exercise-related fatigue. Scientific evidence in this regard is mixed and no conclusive evidence is available at present.

CoQ10 to treat gum disease

Periodontal (gum) disease occurs due to an inflammatory process that arises due to bacterial attack that triggers an inflammatory response in the body. Due to its antioxidant properties, some studies have examined whether coenzyme Q10 may possibly be effective as a topical treatment (i.e. when it is applied directly to the gums) and/or adjunctive treatment for gum infection (periodontitis)43,44.

While the preliminary results are promising, at this stage there is insufficient data to draw conclusive results and further research is required.

Coenzyme Q10 for weight loss

Coenzyme Q10 (in the form of ubiquinol and ubiquinone) is often marketed as a weight loss supplement due to its role in boosting cellular energy and because of the fact that mitochondrial dysfunction plays a role in obesity.

The thinking is that low levels of CoQ10 can lead to decreased energy levels and a sluggish metabolism and supplementation can correct this issue, and thus, aid in weight loss.

There is, however, little in the way of solid evidence involving human trials to support this claim at present.

When it comes to supplementation which is better ubiquinol or ubiquinone (CoQ10)?

While many companies market ubiquinol as the ‘active’ or ‘superior’ form of CoQ10, this is more of a marketing claim than a scientific fact. The truth of the matter is that both forms of CoQ10 are active in various functions. Ubiquinone is active during cellular energy production while ubiquinol is active in the antioxidant protective process45.

In addition, both forms are efficient at increasing the circulating levels of total CoQ10 in the body. The term 'total CoQ10' refers to the sum of both ubiquinol and ubiquinone in the body, as CoQ10 readily switches between the two forms as is required for various bodily functions.

That said, the form that is most beneficial really depends on your age and what you are taking CoQ10 for. Studies show that younger individuals seem to use CoQ10 (i.e. ubiquinone) supplements quite well. However, the body’s ability to convert ubiquinone to ubiquinol reduces with age, which means that ubiquinol, while generally more expensive, is often the more obvious choice for those over the age of 40.  

The conversion of ubiquinone to ubiquinol may also be compromised by certain diseases or genetic conditions. For example, people with genetic single nucleotide polymorphism (SNP) called NQO1 lack the enzyme required by the body to convert CoQ10 to ubiquinol. As such, in those with these types of diseases or genetic conditions, using ubiquinol rather than ubiquinone is required in order to gain any benefit. Research shows that Hispanic and Chinese populations are especially prone to having this SNP46, 47.

Issues with bioavailability and how to choose a product

When it comes to purchasing ubiquinol and ubiquinone oral supplements, it’s important to be aware of the fact that the majority of the supplement is excreted by the body (via faeces) while only small amounts reach the blood, tissues and organs.

There are also high variabilities in absorption depending on the dosage form. Soft gel solubilised capsules have proven to be superior to other available non-solubilised powders (whether delivered in compressed tablets, chewable tablets, powder-filled capsules, and soft gels containing CoQ10 suspended in oil)

When purchasing ubiquinol or CoQ10, look out for products that use VESIsorb® technology in their manufacture. This specialised process enables the improved delivery of ubiquinol as it mimics the natural biological process that transports fat-soluble molecules through the gastrointestinal tract and across what it is referred to as the ‘unstirred water layer’ that exists between the lumen of the gut and the actual cells. This method of ‘transport’ of fat-soluble nutrients like ubiquinol improves delivery to the absorptive epithelium which, in turn, makes for more effective uptake.

For those who opt to take ubiquinone, be sure to select a product that contains 100% natural trans-isomer. If you can’t fine the word ‘trans’ on the labelling, then you may be looking at a product that contains a synthetic version that is not as effective.

While ubiquinol is often the more expensive form of CoQ10, lower doses are usually required to achieve the same results.

For all versions except those that have been specifically designed to be water-soluble, it is important to note that these supplements should not be taken on an empty stomach but rather with food, and where possible with small portions of healthy fatty foods (like avocado, fatty fish like salmon or mackerel) or oils (olive oil, coconut oil etc.) in order to increase absorption and bioavailability.

Coenzyme Q10 Dosage

As a supplement CoQ10 (in the form of ubiquinone or ubiquinol) is available in tablet, capsule and IV form. Tablets and capsules generally range from 25mg to 100mg.

There is no clinically established dose of CoQ10. Oral dosage largely depends upon:

  • The form of CoQ10 being taken – ubiquinol dosage is generally lower than ubiquinone dosage
  • Existing blood levels and what blood levels are being targeted

As a dietary supplement the general guideline most manufacturers recommend taking between 100mg and 300 mg per day.

Recommended use is generally as follows:

100 mg per day – Maintenance dose
200 mg per day – To replenish ubiquinol levels
300 mg per day – For low levels of CoQ10 or to dose load initially and then decrease to 200 mg

It’s important to remember that different brands have different ingredients and strengths and so home use should be administered according to the detailed instructions provided.

Coenzyme Q10 dosage under a physician's care

Higher dosages ranging from 450 to 1200 mg per day may be recommended by physicians when being used as adjuvant therapy in the treatment of various health conditions. The dosage will depend on the individual and condition being treated and will be prescribed by the treating physician.

Daily doses of coenyme Q10 exceeding 100mg

The efficiency of absorption of CoQ10 decreases significantly at higher dosages. As such, in cases where the daily dosage of CoQ10 exceed 100mg, the maximum benefit is attained by dividing dosages into two or three smaller doses spread over the course of the day rather than taking a single large dose49.

Coenzyme Q10 safety


Based on the trials conducted to date, many of which used high dose Coenzyme Q10 (i.e. 1200mg), CoQ10 is generally regarded as safe for adults to take orally.


Coenzyme Q10 should not be used in children without medical supervision.

Using Coenzyme Q10 when pregnant or breastfeeding

At present there is not enough data to conclusively determine the safety of CoQ10 use in pregnancy. The evidence to date suggests that it is possibly safe to take CoQ10 (ubiquinone / ubiquinol) from the 20th week of pregnancy until delivery. Insufficient evidence exists with regard to CoQ10 use while breastfeeding. It is therefore best to avoid its use unless otherwise instructed by your primary healthcare physician or gynaecologist.

Coenzyme Q10 / Ubiquinone / Ubiquinol side effects

The majority of people seem to tolerate CoQ10 in both forms (ubiquinone and ubiquinol) well. In instances where side effects do occur, they are generally more common at higher doses of 1,200mg per day (or more)50. Still, they are usually mild and may include the following:

  • Stomach upset / diarrhoea
  • Loss of appetite
  • Nausea
  • Vomiting
  • Allergic skin rash (this requires medical attention)
  • Low blood pressure

Dividing doses into two or three smaller ones instead of taking a single large dose can help to minimise the adverse side effects.

Coenzyme Q10 Precautions and Warnings


Those undergoing chemotherapy with alkylating agents (i.e. medications like busulfan, carboplatin, cisplatin, Cytoxan, dacarbazine, thiotepa and many others) should exercise caution when taking CoQ10 as there is some concern that it may reduce the effect of these medications. This is why it is important to always ensure that your oncologist is aware of all of the supplements and medications you are taking.

High or low blood pressure (hyper- or hypotension)

Coenzyme Q10 may lower blood pressure. If you are taking medications to manage these conditions, this may result in unwanted side effects. It is therefore important to always discuss all medications and supplements with your doctor and to not start taking CoQ10 or adjust your existing medication until you do.


Those undergoing surgery should discuss the use of CoQ10 with their surgeon prior to surgery as this supplement may interfere with blood pressure control. It is generally recommended that you stop using it at least two weeks prior to a scheduled surgical procedure.

Coenzyme Q10 / ubiquinone / ubiquinol  Interactions

Anti-hypertensive medications (i.e. medications for high blood pressure)

Coenzyme Q10 has shown to slightly decrease blood pressure as well as improve the effectiveness of certain medications. As such taking it along with medications for high blood pressure may cause an unwanted drop in blood pressure which could cause adverse side effects.

Some of the high blood pressure medications that interacts with include:

If you take medication for high blood pressure it is always best to chat to your doctor about taking CoQ10 or adjusting your medication dosage to accommodate taking it.

Blood thinners

Some evidence shows that CoQ10 may reduce the effectiveness of certain blood thinners such as Warfarin (Coumadin), Clopidogrel (Plavix) and Anisindione (Miradon), increasing the risk of clotting. This results in the need for greater doses of blood thinners.

As such, if you are on blood thinners it is important to discuss CoQ10 supplementation with your doctor before taking it as doing so will require close, careful monitoring to ensure maintenance of the appropriate levels and continued blood thinning.

Chemotherapy medications

CoQ10 is a powerful antioxidant. There is some concern that antioxidants may reduce the effectiveness of some chemotherapy medications that treat cancer, but conclusive evidence is lacking. As such, it is always advisable to chat to your oncologist before starting any new supplements while undergoing chemotherapy.

Coenzyme Q10 interactions


CoQ10 is regarded as a dietary supplement has some therapeutic treatment of disease, especially in the elderly. Due to the fact that it supports cell health from which overall good health flows, it may be useful in ensuring continued good health.

Until further research is conducted in various fields, it is recommended that you discuss ubiquinol supplementation with your healthcare provider if you intend to use it as a treatment for a specific disease rather than as a just a health supplement and especially if you are already taking prescription medications for the condition in question.


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