Every cell in your body requires energy to function optimally, which comes from ATP molecules.

Glycolysis, the initial step in producing ATP, involves splitting glucose molecules into smaller compounds; one of these being pyruvate.

Coenzyme Q10H2, also known as coenzyme Q, can be found abundantly within mitochondrial inner membranes in its reduced and oxidized forms (CoQ10H2 and ubiquinol respectively), where it plays an essential role in bioenergetics processes as well as helping support an array of antioxidants within cells.

The Big Picture

Coenzyme Q10 (CoQ10) is an indispensable cofactor, necessary for energy production in cells. It works within mitochondria’s inner membrane where it binds with enzyme complexes to convert carbohydrates and fats to ATP–ATP being the energy currency used by all living things. CoQ10 also acts as an antioxidant, protecting mitochondria and proteins against damage by reactive oxygen species (ROS).

CoQ10 (Coenzyme Q10) is a fat-soluble nutrient found in all cells but especially concentrated in mitochondrial matrix of skeletal muscle and heart tissue mitochondria. CoQ10 exists in three oxidation states, fully reduced ubiquinol form CoQ10H2, radical semiquinone intermediate CoQ10H*, and fully oxidized form CoQ10 (Figure 1).

CoQ10 stands out from its competition due to being highly lipophilic – this allows it to easily traverse across lipid membranes – as well as being capable of accepting and donating electrons, giving it unique metabolic properties.

One of the key hallmarks of aging is a decline in energy metabolism, with loss of CoQ10 from mitochondria a primary culprit. Cell damage by ROS and reactive molecules also appears to play an integral part in functional decline associated with ageing.

CoQ10 stands out as an attractive dietary supplement due to its antioxidant and energy activities, making it attractive in many situations, such as statin-associated myopathy syndrome or congestive heart failure. Clinical trials have been performed to investigate its effectiveness for these purposes.

As part of a small, double-blind, placebo-controlled trial for statin-associated myopathy, supplementing coenzyme Q10 with alpha lipoic acid significantly improved fatigue measured using the Fatigue Severity Scale in patients receiving statins versus those who didn’t receive supplementary therapy; however, researchers caution that additional studies need to be completed in order to ascertain whether these results represent true benefits from using coenzyme Q10 supplements in this population of patients.

The Basics

Coenzyme Q10, commonly referred to by its chemical name Ubiquinone, is an essential cellular nutrient. As part of the ubiquinone family, this fat-soluble compound can be found in virtually all cell membranes – particularly mitochondrial ones – as well as three oxidation states and three names; “Coenzyme Q10” was given this moniker due to its unique chemical structure consisting of benzoquinone head group attached to a 10-isoprene side chain chain; thus its name.

Coenzyme Q10 plays an integral part in the process of oxidative phosphorylation, the process by which carbohydrates and fats are converted to energy currency for all cells known as ATP, or energy currency of all cells. Furthermore, coenzyme Q10 serves as a powerful antioxidant that neutralizes reactive oxygen species (ROS) produced during metabolism; without this protection ROS could damage mitochondrial structures and lead to apoptosis (cell death).

Coenzyme Q10 not only supports mitochondria, but it can also bolster your immune system and act as an anti-inflammatory. Its potency lies in inhibiting prostaglandin production which acts as mediators in many health conditions including inflammation and heart disease.

Coenzyme Q10 is produced naturally in our bodies and obtained through diet. Although not considered a vitamin, its chemical structure resembles those of many vitamins. Sources include meat (poultry and fish particularly high concentrations); vegetables; oily seeds/nuts/eggs; eggs; and fruit as food sources of Coenzyme Q10.

Coenzyme Q10 can also be found deposited within lysosomes, an organelle in cells dedicated to digesting cellular debris. Lysosomal enzymes require an acidic pH in order to function effectively; to maintain that, their high concentrations of coenzyme Q10 provide it.

Evidence indicates that low levels of Coenzyme Q10 may be linked to various health conditions, including heart disease and cancer. Supplementing oral coenzyme Q10 appears to enhance energy and immunity, as well as being safe during pregnancy and breastfeeding.

The Bottom Line

Coenzyme Q10, also known as coQ10 or QH2, can be found in most organisms’ cells as an essential energy producing compound with antioxidant activity. Soluble in lipids and present in mitochondrial membranes where it participates in oxidative phosphorylation reactions, CoQ10 has two isoprenyl chemical subunits connected by benzoquinone groups that accept and donate electrons; its three possible oxidation states include reduced (ubiquinol), semiquinone radical intermediate CoQ10H* and fully oxidized (ubiquinoneO).

Biosynthesis of ubiquinone requires pantothenic acid (vitamin B5) and pyridoxine (vitamin B6) as raw materials; these components are converted to coenzyme A and benzoquinone respectively during biosynthesis, which in turn impacts tissue concentrations of coenzyme Q10. Dietary intake levels of these nutrients is key in determining tissue concentrations of coenzyme Q10.

Supplemental coenzyme Q10 has long been used to treat conditions affecting both the heart and nervous systems. Studies have demonstrated its benefits in patients suffering from chronic heart failure, high blood pressure and chest pain, such as shortness of breath and leg swelling (edema). Furthermore, coenzyme Q10 supplementation may prevent maternally inherited diabetic autosomal dominant hyperglycemia-deafness syndrome (MIDD), caused by mutations in mitochondrial DNA passed down from mother to son (maternally inherited diabetic autosomal dominant hyperglycemia-deafness syndrome MIDD). Research suggests long-term coenzyme Q10 supplementation may improve insulin secretion while hearing loss among these patients.

Research shows that supplementing coenzyme Q10 improves heart function in those suffering from non-ischaemic cardiomyopathy, angina, atrioventricular block and migraine headaches; additionally it may prevent muscle damage and low grade inflammation associated with intense exercise.

Studies have also suggested that supplemented coenzyme Q10 could decrease side effects associated with some medications, including blood thinners such as warfarin and clopidogrel, and heart-related side effects associated with betaxol – used to treat glaucoma. More research must be completed to confirm these findings.

The Future

Coenzyme Q10 in its reduced form (CoQ10H2) is an effective fat-soluble antioxidant. It works to prevent cell membrane and low-density lipoprotein oxidation as well as protect mitochondria from oxidative damage (1, 2). Furthermore, CoQ10 has also been found to protect human cells against lipid peroxidation (81). Furthermore, reduced CoQ10 is easily recycled back from its semiquinone radical precursor CoQ10H* by enzymes known as NAD(P)H oxidoreductases (9).

Supplementation with reduced forms of CoQ10 is widely utilized by people suffering from energy-related health conditions, such as muscular dystrophy and cardiovascular conditions. Studies have demonstrated its efficacy at decreasing oxidative stress and improving exercise performance – particularly among fibromyalgia patients (10). A small placebo-controlled trial combined Lyrica (pregabalin) with CoQ10 supplementation revealed significant pain reduction, improved quality of life metrics and boosting two key antioxidant levels (reduced glutathione and superoxide dismutase). It was well tolerated (12).

Coenzyme Q10’s benzoquinone head group can accept and donate electrons, making it a useful redox cofactor (10). Coenzyme Q10, together with its reduced conjugate, are essential for mitochondrial respiration in all organisms; its reduced conjugate is present in cell membranes of most organisms and mitochondria where it serves as an electron carrier. Furthermore, its unique ubiquinone structure gives coenzyme Q10 the unique property of existing in three oxidation states: fully reduced (CoQ10H2); semiquinone radical intermediate CoQ10H* and fully oxidized ubiquinone CoQ10(3′).

Coenzyme Q10 plays many vital roles, beyond energy production and mitochondrial redox, within metabolic pathways. Studies have implicated it in modulating inflammation processes as well as helping maintain normal endothelium function (13). Furthermore, animal models have demonstrated its antiatherosclerosis properties.

Due to its higher price point and limited bioavailability (only 3-4% is actually absorbed by intestinal tissues), CoQ10 supplements have not become as ubiquitous as omega-3 or probiotic products; however, thanks to emerging research proving their health benefits. Yet CoQ10 will likely gain acceptance over time as evidence accumulates supporting its uses.