Asst. Prof. Muhammet Sait Toprak
Faculty Member - Istanbul Kent University, Faculty of Pharmacy, Department of Biochemistry
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Map of Health content is prepared with an evidence-based approach. References are provided for transparency.
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This content is for informational purposes only and does not replace professional medical advice, diagnosis, or treatment. If you have an urgent medical concern, seek immediate care.
"“Coenzyme Q10 energizes our cells and supports the immune system.”"
Our Energy Source: Coenzyme Q10

What is coenzyme Q10?

Coenzyme Q10 is a vitamin-like substance mostly but not exclusively found in the in organs with high energy metabolism such as the heart, brain, liver, and kidney. It is vital for many events related to energy production. It also supports the immune system.

Antioxidant effect of coenzyme Q10

Coenzyme Q10 is a very powerful antioxidant and plays a very important role in protecting cells from the effects of oxidative stress. It can protect cell membranes, LDL cholesterol (the good type of cholesterol), cell proteins, and DNA from oxidative damage. Coenzyme Q10 also helps restoring other antioxidants such as vitamin C or E. Due to these properties, Coenzyme Q10 is listed among the important exogenous antioxidant supplements.

Other effects of coenzyme Q10

Coenzyme Q10 can regulate fat synthesis in the body and prevent abnormal fat accumulation in the liver. It also helps regulating the inflammatory response. Studies have shown that inflammation was significantly reduced in people with various chronic diseases who used coenzyme Q10 supplement in the dose of 100-300 mg per day for 3 months. Additionally, coenzyme Q10 directly affects the endothelium, causing vasodilation and lowering blood pressure. A clinical study involving 684 individuals showed that coenzyme Q10 supplementation significantly reduced systolic blood pressure.

Coenzyme Q10 deficiency

Regarding to its important role in the vitality cycle, it is understandable that why coenzyme Q10 deficiency impairs energy production in the cells. Due to the high energy demands placed on the whole body, it can affect any part of it, especially the brain, muscles, and kidneys. Coenzyme Q10 deficiency symptoms can vary with age; while symptoms may dramatically appear in infancy, they may not even be observed at all when the person is older.

Coenzyme Q10 deficiency can also impair the body's defence systems against oxidative stress caused by hyperglycemia in patients with diabetes. Studies have showed that diabetic patients have significantly lower levels of coenzyme Q10 comparing to healthy individuals.

A serious decrease in coenzyme Q10 levels can lead to the onset of cancer. Many studies have indicated that patients with lung, pancreatic, and breast cancer have lower plasma coenzyme Q10 levels than non-cancerous individuals. 

Coenzyme Q10 deficiency can lead to other serious problems in various organs. In brain tissue, it can cause ataxia and many other neurological symptoms. In kidney tissue, it causes nephrotic syndrome and kidney dysfunction, eventually leading to kidney failure. In heart tissue, it causes the weakening of the heart muscle due to low energy, which is characteristic of hypertrophic cardiomyopathy.

What are the symptoms of coenzyme Q10 deficiency?

Coenzyme Q10 has extremely beneficial effects on almost every system; therefore, its deficiency can be manifested by a wide spectrum of health issues. These issues occur with various symptoms. The symptoms of coenzyme Q10 deficiency can be listed as follows:

Immune system disorders and weakness

Heart problems

Lack of energy, fatigue, and weakness

Imbalance in cholesterol and blood pressure levels

Muscle pain

Some skin problems; dryness, wrinkles, acne, and tone inequalities

What are the foods rich in coenzyme 10?

Red meat

Chicken meat

Salmon, mackerel

Broccoli, cauliflower

Offal

Vegetable oils such as olive oil and corn oil

Eggs and dairy products

Coenzyme Q10 supplementation

Since coenzyme Q10 is synthesized in all tissues, the body is not normally dependent on exogenous supplementation; however, endogenous biosynthesis tends to decline with age. Furthermore, tissue coenzyme Q10 may be compromised in many pathophysiological conditions. Under these conditions, exogenous coenzyme Q10 supplementation may be required to maintain normal blood and tissue levels.

It is available as a supplement in the capsule forms containing 30, 60, 100, 200, 300, 400, and 600 mg of active ingredient. Although there is no established minimum or maximum effective dose, the average dose required to achieve a therapeutic blood level of 2.5 mcg/ml is 100 mg taken twice daily with food. Daily doses of 100 to 400 mg have been used in cardiology studies, while doses of 600 to 3000 mg have been used in neurodegenerative diseases (Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis).

Coenzyme Q10 supplementation and diabetes

Coenzyme Q10 can be used in the treatment of metabolic syndrome and type 2 diabetes due to its antioxidant properties. A study reported that coenzyme Q10 treatment (260 mg per day for 11 weeks) in patients with type 2 diabetes could significantly reduce fasting blood sugar levels. It has been suggested that exogenous supplementation of coenzyme Q10 may improve glycemic control in diabetic patients. Furthermore, recent clinical studies have linked insulin resistance to a decrease in the amount of coenzyme Q10 in the body and suggest that exogenous coenzyme Q10 supplementation may restore insulin sensitivity.

Coenzyme Q10 supplementation and cardiological diseases

A 2-year treatment with coenzyme Q10 (300 mg/day) as an adjunct therapy in a study of 420 patients with chronic heart failure showed improvement in symptoms and a reduction in major cardiovascular events. A study of the effects of long-term treatment with coenzyme Q10 (200 mg/day) plus selenium in a healthy Swedish elderly population showed a significant reduction in cardiovascular mortality compared to those whom were not treated during the 4-year treatment period.

Coenzyme Q10 supplementation and neurological diseases

Clinical studies have shown that coenzyme Q10 can reduce the loss of dopaminergic neurons in Parkinson's patients. Experimental studies on animal models report that coenzyme Q10 can protect against nerve cell damage caused by injuries. Coenzyme Q10 is also effective in the treatment of Alzheimer's disease thanks to its antioxidant properties. In a study conducted with a pediatric patient group consisting of 1550 cases with frequent headache complaints, plasma coenzyme Q10 levels of individuals were low, and it was stated that both headache frequency and migraine assessment questionnaire scores were significantly reduced when 3mg/kg/day coenzyme Q10 was given to individuals with low plasma coenzyme Q10 levels for 97 days. For these reasons, it is suggested that coenzyme Q10 supplementation may benefit patients suffering from neurodegenerative diseases.

Points to consider when using coenzyme Q10

There is no known absolute contraindication for coenzyme Q10, but caution should be taken in pregnant or breastfeeding women or young children.

Side effects related to coenzyme Q10 are rare. Less than 1% of patients may experience discomfort such as decreased appetite, diarrhea, dizziness, indigestion, and nausea/vomiting.

Taking coenzyme Q10 supplements with the warfarin (coumadin) may reduce the effectiveness of the drug.

Due to the potential hypoglycemic and hypotensive effects of coenzyme Q10, monitoring (follow-up) is recommended, especially when used with prescription drugs.


Asst. Prof. Muhammet Sait Toprak
Asst. Prof. Muhammet Sait Toprak
Faculty Member - Istanbul Kent University, Faculty of Pharmacy, Department of Biochemistry

Arenas-Jal M, et al., Coenzyme Q10 supplementation: Efficacy, safety, and formulation challenges. (2020). 

Bagheri S, et al., Neuroprotective effects of coenzyme Q10 on neurological diseases: a review article. (2023).

Gasmi A, et al., Coenzyme Q10 in aging and disease. (2024).

Garrido-Maraver J, et al., Clinical applications of coenzyme Q10. (2014).

Guerra R and Pagliarini DJ, Coenzyme Q biochemistry and biosynthesis. (2023).

Mantle D, et al., Primary coenzyme q10 deficiency: an update. (2023).

McRae MP, Coenzyme Q10 supplementation in reducing inflammation: an umbrella review. (2023). 

Toprak MS, et al., The effect of coenzyme q10 on oxidative stress and endoplasmic reticulum stress in an experimental diabetes model. (2023).

Zhang SY, et al., Effectiveness of coenzyme q10 supplementation for type 2 diabetes mellitus: a systematic review and meta-analysis. (2018).

Zozina VI, et al., Coenzyme Q10 in cardiovascular and metabolic diseases: current state of the problem. (2018). 

FAQ

CoQ10 supports mitochondrial energy production and acts as an antioxidant. Levels may decline with age and can be affected by statins; use is best goal-driven and product-specific.

Symptoms are non-specific. True deficiency assessment is clinical (history, meds, conditions) and may include plasma testing interpreted in context (lipids, lab ranges).

Plasma CoQ10 testing (total or reduced/total) exists, but interpretation must consider lipid transport and clinical context; rule out common causes of fatigue first.

Yes—specialized labs measure plasma total and/or reduced CoQ10. Results should be interpreted with lipid levels and clinical context; it is not a routine fatigue test.

Fruits may contain small amounts, but they are not major sources. CoQ10-rich foods are more often meats/organ meats and some fatty foods; fruit benefits are mainly other antioxidants.

Some meta-analyses suggest CoQ10 can reduce fatigue scores in certain contexts, but fatigue is multi-causal; use it as a time-bounded, goal-tracked trial after ruling out common causes.

CoQ10 is not a proven weight-loss supplement. At best, it may indirectly support activity via energy/fatigue pathways; sustainable weight loss requires diet, movement, sleep, and adherence.

Common side effects are mild GI symptoms. Key concern is drug interactions (e.g., warfarin/INR). People on BP/diabetes meds or cancer therapy should consult clinicians.

Often yes, but caution with anticoagulants and arrhythmia risk (omega-3). Use should be goal-based and clinician-guided in high-risk groups.

Daily omega-3 can help certain goals (e.g., triglycerides) but may cause GI effects and, at higher doses, raise bleeding/atrial fibrillation concerns. Prefer food-first; supplement by indication.

No. Collagen is a structural protein; CoQ10 is a cofactor for energy production and an antioxidant. They target different pathways and are chosen based on goal.

The strongest evidence is for diabetic peripheral neuropathy symptom relief (commonly around 600 mg/day in studies). Other claims exist but are less consistent; caution with glucose-lowering meds.

Generally yes. They work in different antioxidant domains (fat- vs water-soluble). Use goal-based dosing; consider GI tolerance and medication interactions (e.g., warfarin with CoQ10).

Some meta-analyses show modest improvement signals, but evidence is limited and heterogeneous. CoQ10 is not a replacement for depression treatment—only a potential adjunct in selected cases.

Use is goal-based (energy, statin-related symptoms, etc.), typically taken with meals due to fat solubility, and evaluated as a time-bounded trial. Caution with warfarin and other meds.

Strongest evidence is triglyceride lowering (dose-dependent). Other areas (inflammation, joints, dry eye) are more variable. Consider AF/bleeding risk at higher doses and individualize use.

CoQ10 supports mitochondrial energy and lipid-phase antioxidant defense; ALA is a broad redox antioxidant (water+fat soluble), best evidenced for diabetic neuropathy symptoms. Combination is possible but should be goal-driven.

Typically with meals (both are fat-soluble), prioritizing consistency. In high-risk medication/arrhythmia contexts, suitability matters more than timing.

Evidence is not broad enough to recommend for all kidney issues. In CKD, foundational management dominates; consider CoQ10 only with clinician guidance and clear indication.

Clinical evidence for prostate outcomes is limited. Do not replace urologic evaluation/treatment with supplements; consider CoQ10 only as a general adjunct if there is a separate indication.

Generally yes, but individualize for diabetes meds (ALA may lower glucose) and anticoagulants (CoQ10/INR concerns). Add one at a time to track effects.

There is no single “best” brand. Choose by objective quality: clear form (ubiquinone/ubiquinol), dose transparency, stability, third-party testing, GMP manufacturing, and trustworthy supply chain.

Benefits depend on CoQ10 itself (energy/antioxidant pathways), not the brand. Evidence exists for select goals (fatigue, statin-related symptoms), but outcomes vary; monitor results and consider medication interactions.