Coenzyme Q10
Also known as: CoQ10, Ubiquinone
What Does Coenzyme Q10 Measure?
Coenzyme Q10 (CoQ10), also known as ubiquinone, is a fat-soluble, vitamin-like compound found in virtually every cell of the human body. A blood test measuring CoQ10 quantifies the concentration of this molecule in the plasma or serum, typically expressed in micrograms per milliliter (mcg/mL) or micromoles per liter (µmol/L). CoQ10 exists in two primary forms: ubiquinone (the oxidized form) and ubiquinol (the reduced, active antioxidant form). The test reflects both the body's ability to synthesize CoQ10 internally and the dietary intake from food sources such as organ meats, fatty fish, and nuts.
Why Does Coenzyme Q10 Matter?
CoQ10 plays an indispensable role in mitochondrial energy production, acting as a critical electron carrier in the electron transport chain where ATP — the cell's primary energy currency — is generated. Beyond energy metabolism, CoQ10 is one of the body's most potent fat-soluble antioxidants, protecting cell membranes and mitochondrial DNA from oxidative damage. Low CoQ10 levels have been associated with a range of conditions including heart failure, statin-induced myopathy, neurodegenerative diseases, infertility, and chronic fatigue. Because CoQ10 synthesis naturally declines with age and is significantly depleted by statin medications, measuring levels can guide supplementation decisions and help explain symptoms like persistent muscle pain, fatigue, and cognitive decline.
Normal Ranges
Males
0.70–1.00 mcg/mL (0.81–1.16 µmol/L)
Females
0.70–1.00 mcg/mL (0.81–1.16 µmol/L)
Children
Varies by age; generally 0.40–0.90 mcg/mL; lower in infants and young children
Causes of High Levels
- CoQ10 supplementation (most common cause of elevated levels)
- High dietary intake of CoQ10-rich foods such as organ meats and fatty fish
- Hyperlipidemia or high LDL cholesterol (CoQ10 is transported in LDL particles)
- Certain metabolic or mitochondrial disorders causing compensatory upregulation
- Obesity or excess adipose tissue storing fat-soluble CoQ10
- Use of supplements containing ubiquinol (the more bioavailable reduced form)
Causes of Low Levels
- Statin medication use (HMG-CoA reductase inhibitors block the mevalonate pathway used for CoQ10 synthesis)
- Advancing age (endogenous production declines significantly after age 40)
- Mitochondrial diseases and inherited CoQ10 biosynthesis deficiencies
How to Improve Your Coenzyme Q10
Diet
- Eat organ meats such as beef heart, liver, and kidney, which are among the richest dietary sources (2–3 mg CoQ10 per 100g)
- Consume fatty fish like sardines, mackerel, and salmon several times per week (up to 0.7 mg per 100g)
- Include nuts and seeds, particularly peanuts, sesame seeds, and pistachios, as plant-based CoQ10 sources
- Add muscle meats like beef, pork, and chicken to regular meals, which provide moderate CoQ10 content
- Use heart-healthy oils such as soybean or canola oil, which contain small but meaningful amounts of CoQ10
Supplements
- CoQ10 as ubiquinol (reduced form): 100–300 mg/day for general support; ubiquinol has up to 3x better bioavailability than ubiquinone
- CoQ10 as ubiquinone: 100–200 mg/day taken with a fat-containing meal to maximize absorption
- For statin users: 100–200 mg/day of CoQ10 is commonly recommended to offset drug-induced depletion
- For heart failure or severe deficiency: 300–600 mg/day under medical supervision, divided into 2–3 doses
- Combine CoQ10 with vitamin E (200–400 IU/day) and omega-3 fatty acids to enhance antioxidant synergy and absorption
Related Biomarkers
Frequently Asked Questions
Should I take CoQ10 if I'm on a statin medication?
Statin medications work by blocking the mevalonate pathway, which is the same biochemical pathway your body uses to synthesize CoQ10. This means statins can reduce CoQ10 blood levels by 25–50%, which may contribute to common statin side effects like muscle pain, weakness, and fatigue (myopathy). Many physicians and integrative medicine practitioners recommend 100–200 mg of CoQ10 daily for patients on statins, although large clinical trials have shown mixed results. If you are experiencing muscle-related symptoms while on statins, it is worth discussing CoQ10 testing and supplementation with your doctor.
What is the difference between ubiquinone and ubiquinol?
Ubiquinone is the oxidized form of CoQ10 and the most commonly found form in supplements historically. Ubiquinol is the reduced, active antioxidant form that makes up the majority of CoQ10 in healthy human blood. Ubiquinol is generally considered more bioavailable, meaning your body absorbs and utilizes it more readily — studies suggest it may have up to 3 times greater absorption than ubiquinone. For younger, healthy individuals, the body can efficiently convert ubiquinone to ubiquinol. However, for older adults (over 40), people with chronic illness, or those on statins, ubiquinol supplementation may be preferable due to a reduced capacity for this conversion.
What symptoms suggest low CoQ10 levels?
Low CoQ10 levels do not always produce obvious symptoms, but common signs can include persistent fatigue and low energy despite adequate sleep, muscle weakness, pain, or cramping (especially in statin users), brain fog or difficulty concentrating, poor exercise tolerance, and heart palpitations or shortness of breath in those with cardiovascular conditions. Because these symptoms overlap with many other conditions, a blood test is the most reliable way to confirm deficiency. People at highest risk include those over 40, statin users, individuals with heart failure or diabetes, and people with a family history of mitochondrial disorders.