Coenzyme Q10 (CoQ10)

Health Tips / Coenzyme Q10 (CoQ10)

What Is It?

One of the world’s most popular supplements, the chemical coenzyme Q10 (CoQ10) has generated great excitement as a heart disease remedy and a cure for countless other conditions. The body naturally produces this compound, which has been dubbed “vitamin Q” because of its essential role in keeping all systems running smoothly. In fact, the scientists who identified coenzyme Q10 in 1957 initially honored its ubiquitous presence–it’s found in every human cell and in all living organisms–by naming it “ubiquinone.” Small amounts are also present in most foods.

A member of a family of compounds called quinones, coenzyme Q10 (sometimes called Co Q10) works in concert with enzymes (hence the name “coenzyme”) to break down and convert food into energy. It is particularly abundant in high-energy-demanding cells, such as those found in the heart. In addition, coenzyme Q10 acts as a powerful antioxidant to prevent the cellular damage caused by unstable oxygen molecules called free radicals.

Health Benefits

Extravagant claims have been made for coenzyme Q10, many of which require further investigation. Still under examination, for example, is whether it can truly slow the progress of Parkinson’s disease, boost stamina in AIDS patients, stabilize blood sugar levels in diabetes sufferers, enhance athletic ability, improve circulation in Raynaud’s disease, fight allergies and stave off the retina deterioration associated with macular degeneration. Skeptics also question the value of taking coenzyme Q10 in pill form. They contend that it loses its potency while traveling through the digestive tract.

On the other hand, there is evidence to indicate that coenzyme Q10 does work for certain disorders. Most importantly, it appears to support the heart muscle’s strenuous efforts to beat 100,000 times a day. Without adequate levels of this enzyme, the heart muscle can become weaker and less efficient at pumping blood through the body. Coenzyme Q10’s popularity as a heart supplement is well established in countries such as Sweden, Italy, and Canada. In Japan, up to 10% of adults take coenzyme Q10 regularly.

Specifically, coenzyme Q10 may help to:

Treat heart disease, especially congestive heart failure. Heart disease sufferers tend to be relatively deficient in coenzyme Q10. When levels are boosted by supplements, heart function appears to be enhanced. In addition, the compound’s antioxidant properties may inhibit artery-clogging plaque buildup and potentially fatal blood clots. People with congestive heart failure, in which a weakened heart pumps inefficiently, may stand to benefit the most from coenzyme Q10 supplements. In a 12-month placebo-controlled trial of more than 2,500 people suffering from this disease, 80% experienced an improvement in symptoms–less ankle swelling and shortness of breath, and better color and sleep habits–when they supplemented their standard medications with a daily 100 mg dose of coenzyme Q10. They were also far less likely than placebo-takers to require hospitalization for their condition. Rates of death from the disease did not change, however.

Not all studies have reported benefits, though. In a recent six-month trial of 46 individuals with moderate to severe congestive heart failure, those assigned to take coenzyme Q10 (rather than a placebo) experienced no apparent improvement in heart function or symptom relief. Clearly more research is needed to prove conclusively that coenzyme Q10 is effective for this potentially fatal disease.

Treat angina and arrhythmias. The intense chest pain known as angina may occur less frequently under the influence of coenzyme Q10’s heart-enhancing actions. In lightening the heart’s workload and steadying heart rhythm, coenzyme Q10 may be particularly useful for people who suffer from irregular heart beats (arrhythmias) following a heart attack.

Control high blood pressure. More than a third of people suffering from high blood pressure–a serious but symptom-free ailment known as the silent killer–are believed to have inadequate amounts of coenzyme Q10. Taking the supplement regularly may help to lower elevated blood pressure and protect against complications of the disease.

Prevent and treat cancer. Coenzyme Q10’s antioxidant actions can be enlisted to stop the free-radical damage believed to cause certain cancers. Several small studies have shown a benefit for people with breast or prostate cancer. Other findings indicate that coenzyme Q10 boosts the immune system, possibly helping to limit the spread of cancerous tissue. Clearly more research is needed.

Counter Alzheimer’s disease and memory loss, and provide general anti-aging benefits. Because the body’s production of coenzyme Q10 slows with age, some doctors routinely recommend the supplement to anyone over age 50. Indeed, many people take it as a general energy enhancer; others take it to fight age-related memory loss. Its antioxidant actions have even been enlisted to slow the progression of Alzheimer’s disease, a memory-robbing, degenerative disease most common in older individuals. Further research is needed to flesh out exactly how supplemental coenzyme Q10 and its antioxidant properties might positively affect the aging process.

Fight weight gain, chronic fatigue syndrome, fibromyalgia, Parkinson’s disease, and HIV/AIDS. In addition to being a powerful antioxidant, coenzyme Q10 helps provide the spark that generates the body’s energy on a very basic, cellular level. Without adequate stores of this nutrient, the body will have fewer resources with which to to fight off frequently debilitating disorders such as chronic fatigue, fibromylagia, and Parkinson’s disease. Even HIV infection may benefit. Getting adequate stores of the nutrient can, at a minimum, help ensure proper muscle function and overall stamina. Smooth energy use on the cellular level may also help in countering weight gain.

Treat gum disease. For people with periodontal disease who must undergo oral surgery, low doses of coenzyme Q10 may promote healing. The supplement is also thought to limit post-surgery gum pain and bleeding. A 1995 review of coenzyme Q10 concluded that there was little sound evidence to support this use, however. Note: Coenzyme Q10 has also been found to be useful for a number of other disorders. For information on these additional ailments, see our Dosage Recommendations Chart for Coenzyme Q10.



Dosage Information

For congestive heart failure, angina, fibromyalgia, and symptoms of Alzheimer’s disease: Take 100 mg twice a day.

For arrhythmias, high blood pressure, anti-aging actions, gum disease, and cancer prevention: Take 50 mg twice a day.

For supplementing conventional cancer therapy: Take 200 mg every morning. Be sure to check our our Dosage Recommendations Chart for Coenzyme Q10, which lists therapeutic dosages for specific ailments at a glance.

Guidelines for Use

Take coenzyme Q10 with food. As a fat-soluble compound, it is absorbed most efficiently when consumed with a food containing some fat, such as peanut butter. For the same reason, look for capsules or tablets that contain coenzyme Q10 in an oil base (such as soybean or another oil).

Keep coenzyme Q10 out of direct light. Store it in a cool area (but not the freezer).

You may have to take coenzyme Q10 for two months or more before seeing any improvement in your condition.

The supplement can be expensive (a daily dose of 100 mg can cost about $40 a month). Shop around for the lowest price on a quality product.

General Interaction

Certain heart medications–statins for high cholesterol, beta-blockers for high blood pressure–may deplete or in other ways lower coenzyme Q10 levels in the body. Ask your doctor about supplementing your heart-treatment regimen with coenzyme Q10.

There are no other known drug or nutrient interactions associated with coenzyme Q10.

Possible Side Effects

Side effects are uncommon, even at high doses.

Rarely, coenzyme Q10 can cause nausea, diarrhea, upset stomach, or appetite loss.


Heart disease is a serious condition. If you suffer from it, talk to your doctor about taking coenzyme Q10 along with conventional medications. It should never be used as a substitute for proven therapies.

If you are pregnant or breast-feeding, don’t take coenzyme Q10 supplements; its safety in this group of women has not been established.


Aging 50-60 mg once a day
Alzheimer’s Disease 50-75 mg twice a day
Angina 60-120 mg twice a day
Arrhythmia 50-60 mg twice a day
Cancer 100 mg twice a day
Cancer Prevention 50-100 mg once a day; may be partially covered by daily antioxidant complex
Chronic Fatigue Syndrome 100 mg a day
Congestive Heart Failure 100 mg twice a day
Fibrocystic Breast Changes 100 mg a day
Fibromyalgia 50-100 mg twice a day
Gum Disease 100 mg once a day; for prevention, 60 mg once a day
Heart Disease Prevention 60-100 mg a day
High Blood Pressure 50-100 mg twice a day; may be partially covered by your daily antioxidant complex.
High Cholesterol 50 mg twice a day. Take in combination with red yeast rice.
Infertility, Male 50-75 mg every morning
Memory Loss/Impairment 60 mg in the morning
Multiple Sclerosis 60-100 mg a day
Stroke 50 mg twice a day
Weight Loss 50 mg twice a day

Doctor Recommendations
David Edelberg, M.D.

Also known as ubiquinone (ubi as in ubiquitous, meaning it’s everywhere in the body), coenzyme Q10 is a key enzyme within mitochondria, the energy centers of a cell. It is, in fact, involved with creating 95% of the cellular energy used by the body. I’ve heard nutritionally oriented doctors compare this substance to the spark plug in a cell’s motor for years now and frankly, that’s still the best image of what coenzyme Q10 does. Coenzyme Q10 is also a powerful antioxidant. Studies have shown that taking coenzyme Q10 orally will raise the tissue levels of this substance. And deficiencies in coenzyme Q10 can exist–in fact, they’re actually more common than originally thought. For example, the heart, which has very high coenzyme Q10 levels, can develop congestive heart failure if levels are low. The immune system and the musculoskeletal system have substantial energy requirements, too. And conditions such as HIV or cancer, chronic fatigue or fibromyalgia, all may benefit from additional coenzyme Q10.


Although never clinically tested for either fibromyalgia or chronic fatigue syndrome, many nutritionally oriented physicians will suggest that their patients give this supplement a try, especially to improve flagging energy levels. This is because there are substantial coenzyme Q10 levels in muscle tissue, and depletion could well produce symptoms of fatigue. Coenzyme Q10’s effect on muscles and fatigue has surfaced at least tangentially in two clinical studies. In one small European study, sedentary men reported increased muscle performance and aerobic capacity after taking coenzyme Q10. In another study, patients with muscular dystrophy (obviously a separate condition from fibromyalgia) reported increased muscle strength, reduced leg pain, and less fatigue after taking the supplement. Researchers speculate this may have been due to increased energy production in the muscle cells themselves.


Most of our coenzyme Q10 comes from Japan, where it has been on the government-approved list since 1974 for the treatment of congestive heart failure. It’s a completely natural product, made by fermenting beets and sugar cane with a special strain of yeast.


Coenzyme Q10 is a fat-soluble compound, so look for: Capsules or tablets with an oil base Oil-based softgel capsules are another good option; they appear to help maximize the bioavailablity (or absorbency) of this nutrient.

Combination Products

Although coenzyme Q10 appears in a variety of combination products, the amount present in combinations is usually very small. If you’re going to give this supplement a try for your fibromyalgia, I suggest you get capsules of pure coenzyme Q10.


I’d make sure you’re getting at least 100 mg a day. If you’re taking a combination supplement that can’t provide that, then add more coenzyme Q10 separately.


The safety of using coenzyme Q10 during pregnancy or breast-feeding has not been established, so it’s best to avoid it during those situations.

Be well,
David Edelberg, MD