What Does CoQ10 Do in the Body?

December 5, 2025 •

4 min read

In every cell of your body, a vitamin-like molecule called coenzyme Q10 (CoQ10) is hard at work, with its highest concentrations found in organs with high energy demands, like the heart and liver. It is a vital component of the energy production process within your cells and also acts as a potent antioxidant.

Quick Summary

This guide explains the dual functions of CoQ10 in the body: facilitating cellular energy production within mitochondria and acting as a powerful antioxidant to protect against free radical damage. It covers how CoQ10 levels naturally decline with age and outlines the primary roles and potential benefits of this essential compound.

Key Points

Essential for Energy Production: CoQ10 is a key component of the mitochondrial electron transport chain, which generates the body's primary energy source, ATP.
Potent Antioxidant: It protects cells and lipids from damage caused by free radicals and oxidative stress.
Concentrated in Vital Organs: Highest concentrations are found in organs like the heart, liver, and kidneys, which have high energy requirements.
Levels Decline with Age: Natural production of CoQ10 in the body decreases with age, and can be further affected by diseases or statin use.
Two Forms for Supplementation: CoQ10 is available as ubiquinone (oxidized) and ubiquinol (reduced). Ubiquinol is the active form and may offer better bioavailability for some individuals.
Supports Heart and Brain Health: Supplementation may benefit heart function and protect against age-related neurodegenerative diseases by improving cellular energy and reducing oxidative damage.
Found in Foods: Dietary sources include organ meats, fatty fish, and some vegetables, but typically not in high enough quantities to correct a deficiency.

Coenzyme Q10, also known as ubiquinone, is a fat-soluble molecule synthesized naturally within the human body, playing a crucial role in maintaining cellular function and health. It is fundamental to the body's energy creation and protective antioxidant defenses. Though the body produces its own supply, CoQ10 levels can decrease over time due to aging, certain health conditions, and the use of some medications, like statins. For those with lower levels, supplementation or dietary adjustments may be beneficial.

CoQ10's Role in Cellular Energy Production

At the core of CoQ10's function is its indispensable role in the mitochondria, often referred to as the 'powerhouses' of the cell. Mitochondria are responsible for creating adenosine triphosphate (ATP), the primary energy currency for all cellular processes.

Electron Transport Chain: CoQ10 is a key player in the mitochondrial electron transport chain. It shuttles electrons between different enzyme complexes (specifically from complexes I and II to complex III). This electron transfer process is essential for driving the synthesis of ATP.
High Energy Demand: Organs and tissues with high energy needs, such as the heart, liver, and kidneys, have the highest concentrations of CoQ10 to support their intensive metabolic processes.
Redox States: CoQ10 can exist in three different redox states—fully oxidized (ubiquinone), fully reduced (ubiquinol), and the semiquinone radical intermediate. This ability to carry and transfer electrons is central to its energetic role. In circulation, the body primarily converts the consumed ubiquinone into its reduced, active form, ubiquinol.

CoQ10's Function as an Antioxidant

Beyond its role in energy production, CoQ10 is a potent lipid-soluble antioxidant, acting within cell membranes to neutralize harmful molecules called free radicals.

Protects from Oxidative Stress: During the normal process of ATP synthesis, free radicals are naturally produced. While these are managed by the body under normal circumstances, an excess can lead to oxidative stress, causing damage to cellular components like DNA and lipids. CoQ10 helps to prevent this damage by scavenging free radicals.
Regenerates Other Antioxidants: In its reduced form (ubiquinol), CoQ10 has been shown to help regenerate other antioxidants, such as vitamin E, by returning them to their active state.
Protects Lipid Membranes: As a lipid-soluble molecule, CoQ10 is particularly effective at protecting lipid cell membranes from damage caused by free radicals, a process known as lipid peroxidation.

CoQ10 Deficiency and Associated Health Impacts

CoQ10 deficiency, whether due to aging, chronic disease, or statin use, can manifest through various symptoms linked to a decrease in cellular energy and an increase in oxidative stress.

Fatigue and Muscle Weakness: Low CoQ10 levels can directly lead to chronic fatigue and muscle weakness or pain, especially with statin use. These symptoms are the result of insufficient energy production in muscle cells.
Cardiovascular Issues: As the heart relies heavily on CoQ10 for energy, a deficiency is often associated with heart conditions like congestive heart failure and high blood pressure. Supplementation has shown promise in supporting heart function in these cases.
Neurological Decline: Mitochondrial dysfunction, which can stem from low CoQ10, is implicated in age-related neurological diseases such as Parkinson's and Alzheimer's, which are worsened by free radical damage.

Forms of CoQ10: Ubiquinone vs. Ubiquinol

Understanding the two forms of CoQ10 is important, particularly for supplementation, as they represent different stages of the molecule's activity in the body.


Feature	Ubiquinone (Oxidized CoQ10)	Ubiquinol (Reduced CoQ10)
Function	Oxidized form, less readily used by cells until converted.	Active, potent antioxidant form used directly by the body.
Appearance	White or yellowish powder.	Brownish-yellow soft gel or suspension.
Stability	More stable and less prone to degradation.	Less stable and more prone to oxidation.
Bioavailability	Requires the body to convert it to ubiquinol for antioxidant action.	Often higher bioavailability, as it's the body's pre-converted active form.
Recommended For	General supplementation for most healthy individuals.	Older adults or those with impaired absorption who may have difficulty converting ubiquinone.

How to Maintain Healthy CoQ10 Levels

Maintaining adequate CoQ10 levels is possible through a combination of diet and, if necessary, supplementation. It is important to note that dietary intake alone may not be sufficient to significantly raise levels.

Dietary Sources:

Animal Meats: Organ meats like heart, liver, and kidney contain some of the highest concentrations of CoQ10. Muscle meats like beef, pork, and chicken also provide a source.
Fatty Fish: Fish such as salmon, mackerel, and sardines are good dietary sources.
Plant-Based Foods: While containing lower amounts, vegetables like broccoli, nuts such as peanuts and pistachios, and legumes like soybeans offer some CoQ10.

Supplementation:

For individuals with low levels due to aging or medication, supplements are a more direct way to increase CoQ10.
Absorption is improved when supplements are taken with a meal containing fat, as CoQ10 is fat-soluble.
Soft-gel capsules are often cited as having better absorption than other forms.
Individuals should consult with a healthcare provider to determine appropriate supplementation based on their individual needs and health status.

Conclusion

CoQ10 is a foundational molecule for human health, serving the twin functions of cellular energy production and potent antioxidant protection. Its primary role in the mitochondria ensures that organs with high metabolic demands, like the heart and liver, receive the necessary energy to function correctly. Simultaneously, its antioxidant properties safeguard cells from the damaging effects of oxidative stress. As natural CoQ10 production declines with age and is affected by certain health conditions and medications, many people may benefit from supplementation. The choice between ubiquinone and ubiquinol can be tailored to individual needs, with ubiquinol often preferred for its higher bioavailability. By supporting these fundamental cellular processes, CoQ10 contributes significantly to overall vitality, heart health, and protection against age-related decline.

Coenzyme Q10: Dosage, benefits and side effects

Frequently Asked Questions

The primary role of CoQ10 is to aid in the production of cellular energy, known as ATP, within the mitochondria. It also functions as a powerful antioxidant, protecting cells from damage caused by free radicals.

CoQ10 levels naturally decrease with age. They can also be lowered by certain medications, most notably cholesterol-lowering statins, and by chronic health conditions such as heart disease and neurological disorders.

Ubiquinone is the oxidized form of CoQ10, while ubiquinol is the reduced, active antioxidant form. The body must convert ubiquinone to ubiquinol to use it for antioxidant purposes. Some people, particularly older adults, may absorb ubiquinol more efficiently.

While CoQ10 is present in foods like organ meats, fatty fish, and nuts, the amounts found in a typical diet are usually not enough to significantly increase CoQ10 levels, especially if you have a deficiency.

Since statin drugs can lower CoQ10 levels, some research has explored whether CoQ10 supplements can help with statin-associated muscle pain. While some evidence is promising, not all studies have been conclusive, and results are inconsistent.

CoQ10 is generally considered safe for most people, with few and mild side effects like upset stomach or nausea. However, it may interact with blood-thinning medications like warfarin and certain chemotherapy drugs, so a healthcare professional should always be consulted first.

For optimal absorption, CoQ10 supplements should be taken with a meal that contains fat, as it is a fat-soluble compound. Some forms, like soft-gel capsules, are also more easily absorbed by the body.