Evidence

These uses have been tested in humans or animals.  Safety and effectiveness have not always been proven.  Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Key to grades

A
Strong scientific evidence for this use
B
Good scientific evidence for this use
C
Unclear scientific evidence for this use
D
Fair scientific evidence against this use (it may not work)
F
Strong scientific evidence against this use (it likely does not work)

Grading rationale

Evidence gradeCondition to which grade level applies
A

Coenzyme Q10 deficiency

CoQ10 is made naturally in the body, but deficiency may occur due to disease, low dietary intake, or high CoQ10 use by the body. Symptoms of deficiency include heart failure, high blood pressure, and chest pain. Depending on the cause of deficiency, supplementing with CoQ10 or increasing dietary intake may be effective.
B

Heart failure

Early evidence suggests that CoQ10 may be effective for chronic heart failure. Low blood levels of CoQ10 have been associated with this condition. CoQ10 has been used in combination with other herbs and supplements for chronic heart failure.
B

High blood pressure

There is good evidence to support the use of CoQ10 in the treatment of high blood pressure. However, more studies evaluating a higher dose for a longer treatment period are needed.
C

Age-related macular degeneration

Age-related macular degeneration (AMD) is an eye condition that causes vision loss in older adults. Early research suggests that a combination of acetyl-L-carnitine, omega-3, and CoQ10 may improve visual function in early AMD. More research is needed on the effects of CoQ10 alone.
C

Aging

Early study suggests that a combination of CoQ10 and other antioxidants and minerals may improve skin roughness and fine wrinkles. Further research is needed to understand CoQ10's role in skin aging.
C

Alzheimer's disease

There is some evidence that idebenone, a man-made compound similar to CoQ10, may benefit people with Alzheimer's disease. However, the effect of CoQ10 itself is unclear.
C

Amyotrophic lateral sclerosis (ALS)

CoQ10 has been studied for amyotrophic lateral sclerosis (ALS), a disease affecting brain and spinal cord nerve cells that control muscle movement. More research is needed in this area.
C

Antioxidant

CoQ10 has been studied for use as an antioxidant to protect cells from damage. CoQ10 has been used in combination with other antioxidants. Early study suggests that it may have antioxidant benefits in people with heart disease. More information is needed on the potential benefits of CoQ10 alone.
C

Asthma

Early study reports that CoQ10 in combination with vitamin E, vitamin C, and conventional therapy may reduce the dosage of asthma medication required. More research using CoQ10 alone is needed.
C

Breast cancer

Low levels of CoQ10 may be linked to risk of breast cancer. There is promising evidence to support the use of CoQ10 in the treatment of breast cancer, possibly in combination with conventional therapy. More research is needed.
C

Cancer

CoQ10 levels may help predict the risk of skin cancer progression. One study found lower CoQ10 levels in people who have cancer, compared to those who do not. Early research suggests that CoQ10 in combination with other antioxidants may increase survival in end-stage cancer. However, more information is needed on CoQ10 alone.
C

Cataracts

Early study suggests that CoQ10 may benefit eye health. CoQ10 has been used in combination with vitamin A to improve nerve regeneration in the eye. However, the effect of CoQ10 alone is unclear. More research is needed.
C

Chemotherapy side effects

There is unclear evidence to support the use of CoQ10 for side effects of chemotherapy on the heart. Additional research is needed in this area.
C

Chest pain

CoQ10 has been studied for chest pain caused by exercise. More research is needed in this area.
C

Chronic fatigue syndrome

Early research shows that CoQ10 may improve symptoms of chronic fatigue syndrome. More high-quality research is needed in this area.
C

Cocaine dependence

The effect of CoQ10 on cocaine usage is unclear. More research is needed on this topic.
C

Coronary heart disease

CoQ10 used in combination with the cholesterol-lowering drug simvastatin may benefit people who have coronary heart disease. CoQ10 may also help reduce inflammation in those with this condition. Further research on CoQ10 alone is needed.
C

Cystic fibrosis

Low levels of CoQ10 have been found in children with cystic fibrosis, a disease that causes mucus buildup in lungs. Combination products containing CoQ10 have been studied. More research on the effects of CoQ10 alone is needed.
C

Dry mouth

Early research suggests that CoQ10 may improve symptoms of dry mouth. More well-designed studies are needed.
C

Exercise performance

Overall, strong evidence is lacking on the use of CoQ10 for improving exercise performance. CoQ10 may most benefit people who have chronic lung diseases, such as asthma. More research is needed on this topic.
C

Fibromyalgia

Fibromyalgia is a condition in which there is long-term pain and tenderness in the muscles and joints. Early study suggests that people with this disorder may benefit from the use of CoQ10. More research is needed.
C

Gum disease

Early research suggests that CoQ10 levels may be lower in the gum tissue of people with gum disease. There is promising evidence to support CoQ10 for treating gum disease. However, more research is needed.
C

Hearing loss

Low levels of CoQ10 may be associated with a higher risk of hearing loss. Evidence is mixed regarding the use of CoQ10 for hearing loss. More well-designed research is needed.
C

Heart attack

CoQ10 may benefit people who have had a previous heart attack. More studies are needed in this area.
C

Heart disease (chronic myocardial disease)

CoQ10 may have benefits in people with a chronic disease of the heart muscle. More well-designed research is needed.
C

Heart disease prevention

CoQ10 may improve blood flow and blood vessel widening in people with diabetes. A combination of CoQ10 and garlic extract may benefit heart health associated with stress. More high-quality studies are needed on this topic.
C

Heart muscle injury

Research suggests that CoQ10 may benefit people who have cardiomyopathy, a weakening or problem with the heart muscle. Levels of CoQ10 may be lower in people with this condition. More research is needed in this area.
C

Heart protection during surgery

There is promising evidence to support the use of CoQ10 before heart surgery. More studies are needed in this area.
C

High cholesterol

Evidence is conflicting in support of the cholesterol-lowering effects of CoQ10. More research is needed in this area.
C

HIV/AIDS

Early research suggests that evidence is lacking to support of the use of CoQ10 for treating HIV/AIDS. More research is needed in this field.
C

Hypertriglyceridemia

CoQ10 may improve blood pressure and other measures of heart health in people who have high triglyceride levels. Additional research is needed in this area.
C

Immune enhancement

CoQ10 has been studied for immune enhancement. However, details are lacking, and more research is needed on this topic before conclusions can be made.
C

Infant development / neonatal care

Early research suggests that CoQ10 may help treat symptoms of Prader-Labhart-Willi syndrome, a genetic disorder affecting growth and development. More research is needed in this area.
C

Kidney failure

Results are conflicting in support of CoQ10 for the treatment of kidney failure. More well-designed studies are needed.
C

Male infertility

There is early evidence that supports the use of CoQ10 for improving sperm health. More well-designed studies are needed in this area.
C

Migraine

CoQ10 has been studied for use in treating migraines. More well-designed studies are needed before a conclusion can be made.
C

Mitochondrial diseases

CoQ10 has been studied for diseases affecting the mitochondria, which are energy-creating components found in every cell in the body. There is promising evidence to support CoQ10 use for conditions such as Kearns-Sayre syndrome, which may cause drooping eyelids and vision problems. More research is needed in this area.
C

Mitral valve prolapse

Early evidence supports the use of CoQ10 in children with mitral valve prolapse, a condition in which a heart valve does not close properly. More studies are needed this area.
C

Movement disorders

Early evidence suggests that CoQ10 may be useful in treating symptoms of Friedreich's ataxia, a disease that damages the nervous system. More research is needed to confirm whether CoQ10 may benefit people who have this condition.
C

Muscle weakness

CoQ10 may help reduce some side effects of statin therapy, including muscle weakness. More research is needed in this area.
C

Muscular dystrophies

There is mixed evidence in support of CoQ10 or idebenone (a man-made compound similar to CoQ10) for treating muscular dystrophies, diseases in which there is muscle damage or loss. Further study is needed.
C

Myelodysplastic syndrome

CoQ10 has been studied for myelodysplastic syndrome, a condition in which there is cell damage in the bone marrow. Early evidence suggests that CoQ10 may benefit people who have this condition. Further research is needed in this area.
C

Nerve pain

Early research reports that CoQ10 may benefit people who have nerve pain caused by diabetes. More research is needed to confirm these findings.
C

Parkinson's disease

CoQ10 has been studied for the treatment of Parkinson's disease. There is promising evidence in support of the use of CoQ10 for this condition. However, more high-quality studies are needed.
C

Peyronie's disease

CoQ10 may benefit men with Peyronie's disease (abnormal curvature, pain, and scar tissue in the penis) in terms of slowing disease progression and reducing curvature. More well-designed studies are needed in this area.
C

Pre-eclampsia

Early research suggests that CoQ10 may lower the occurrence of pre-eclampsia (high blood pressure during pregnancy) in women who are at risk. Further research is needed in this area.
C

Prostate cancer

A combination product containing CoQ10 lacked benefit in men with prostate cancer. Further study is needed before firm conclusions can be made.
C

Psoriasis

A combination product containing CoQ10 may improve symptoms of psoriasis, an inflammatory skin condition. More research on the effects of CoQ10 alone is needed.
C

Recovery from surgery

CoQ10 combined with the use of conventional drugs may benefit people recovering from skin cancer surgery and reduce recurrence. Although promising, more research is needed to confirm these findings.
C

Ringing in the ears

In early research, people with ringing in the ears and low CoQ10 levels had decreased symptoms with CoQ10 supplementation. More research is needed on this topic.
C

Weight loss

CoQ10 may help promote weight loss in obese people. Levels of CoQ10 may be lower in people with a higher body mass index (BMI). More high-quality research is needed to confirm these findings.
D

Diabetes

Early evidence supports the use of CoQ10 in the treatment of heart-related complications in people with diabetes. However, overall study results suggest that CoQ10 may lack effect on blood sugar control. More research is needed.
D

Hepatitis C

Limited research reports that CoQ10 may lack benefit in people who have hepatitis C. More research is needed on this topic.
D

Huntington's disease

There is negative evidence to support the use of CoQ10 or idebenone (a man-made compound similar to CoQ10) for the treatment of Huntington's disease. More research assessing long-term benefit is needed.

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Abnormal heart rhythms, acidosis (acid buildup in the body), adrenal insufficiency (hormone production problem), anemia, antiviral, autoimmune diseases (lupus), Bell's palsy (facial nerve disorder), blood flow disorders, cardiac ischemia (blocked blood flow to heart), celiac disease (gluten allergy), chronic obstructive pulmonary disease (long-term lung disease), clogged arteries, depression, diabetic foot pain, DIDMOAD (genetic disorder causing diabetes and deafness), dizziness, Down's syndrome, encephalopathy (brain disease), eye disorders (CPEO, a disease causing eye weakness), fluid in the lungs, gallbladder disorders, glaucoma (eye disorder causing optic nerve damage), hair loss, headache, hepatitis B, iatrogenic lipodystrophy (fat storage disorder), inflammation, insomnia, liver protection, lung disease, mental illness, mental performance, metabolic abnormalities, multiple sclerosis, muscle wasting, nutrition, phenylketonuria (inability to break down amino acid), shock, shortness of breath, skin conditions, skin irritation (caused by chemicals), speech disorders, stomach disorders, stomach ulcer, viral myocarditis (heart inflammation caused by virus), vomiting.

This evidence-based monograph was prepared by The Natural Standard Research Collaboration

www.naturalstandard.com