Coenzyme Q10 is found in all of the cells in the human body. It is used for energy production and to support the growth and maintenance of cells. Commonly called CoQ10 it is also found in high levels in organ meats such as liver, kidney and the heart, but can also be found in sardines, soy oil, peanuts and mackerel. CoQ10 functions as an antioxidant that will protect the body from damaging free radicals.

Another function of CoQ10 is to help the body digest foods. It also protects the heart by helping improving the energy in cells and preventing clots from forming in the blood. While it has been approved in Japan for heart failure use, in the United States it is only available as a dietary supplement and not as a medicine.

What CoQ10 Does

CoQ10 is supposed to benefit cardiovascular health and help with conditions such as heart failure, cancer, periodontal disease and even muscular dystrophy. It is thought to be similar to vitamins as it is found in all cells of the body. Many claims tout CoQ10 as a necessary supplement to maintain optimal health and even some medical doctors recommend taking the supplement. However, the potential for CoQ10 side effects exist as with many supplements and natural products.

CoQ10 Side Effects

Because CoQ10 is a substance that is produced naturally in the body, most people do not experience side effects when taking the supplement. A person in good health, not taking other prescription medications, and is using CoQ10 as a preventive supplement will probably not experience any extreme side effects. Since CoQ10 is produced naturally in the body the supplement is basically enhancing what is already there but may have been depleted by lifestyle or diet.

Mild insomnia has been reported in some people who take 100 mg of CoQ10 daily. Other researchers have reported that a person taking 300mg or more daily for an extended period of time may experience elevated levels of liver enzymes, but liver toxicity was not reported.

People have reported allergies when taking increased dosages of CoQ10 and others may experience itching or rashes, but these side effects are not experienced in large numbers of people. Other very mild side effects may include:

•Heartburn
•Loss of appetite
•Diarrhea
•Nausea or vomiting
•Irritability
•Upper abdominal pain
•Fatigue

These mild side effects can be referred to as bothersome, rather than serious.

Serious CoQ10 Side Effects

As with any other supplement or medication, a person taking CoQ10 should discuss the supplement with their physician before they start using it. Since CoQ10 is only regulated in the United States as a dietary supplement there is no real oversight on its manufacturing and production. It is possible that the CoQ10 purchased could have contaminants or contain more or less of the active ingredients that appear on the list of ingredients. Quality may not be consistent, so it is always advisable to purchase the CoQ10 and any other vitamin or supplement from a reputable manufacturer.

There are some side effects that should be discussed with the physician if they occur. These include:

•Fainting or dizziness – this could be a sign of low blood pressure

•Allergic reactions – severe itching and sneezing, wheezing, difficulty breathing or swallowing, unexplained swelling.

Anyone taking medications that regulate blood sugar levels that are generally taken to control diabetes or hypoglycemia should consult with their physician before taking CoQ10. The supplement may have a side effect of lowering levels of blood sugar. This could be a concern for blood sugar levels becoming too low.

The same is true for people on medications that regulate their blood pressure. A potential side effect of CoQ10 may be a decrease in blood pressure. While this may be beneficial to people with high blood pressure, those who already have low blood pressure that is being regulated with medication should be cautious and consult with their physician before taking CoQ10.

Another area of concern is for people who are taking statins, medication for high cholesterol, blood thinners called anticoagulants or Coumadin. These medications can actually decrease the levels of CoQ10 in the body and can make a CoQ10 supplement less than effective.

Cancer patients that are taking chemotherapy or radiation should be aware that a side effect of CoQ10 is to lessen the effectiveness of these treatments.

CoQ10 should not be taken by pregnant women unless under the advice of a physician.
There are certain prescription drugs that may cause interactions when taken with CoQ10, and should be discussed with a physician.

•Chemotherapy drugs – may become less than effective when taken with CoQ10
•Daunorubicin and doxorubicin – chemotherapy medications
•Blood pressure medications
•Blood thinning medications
•Betaxolol – beta-blocker medications used to treat glaucoma
•Fibric acid derivatives – cholesterol medications
•Tricyclic antidepressant medications – including Elavil, Sinequan and Tofranil

Is CoQ10 Effective?

People taking the supplement CoQ10 should be aware of all of the risks as well as determining if it is an effective supplement for well-being. A person that is deficient of CoQ10 that the body naturally produces may benefit from taking the supplement, but this condition is rare. Symptoms include seizures, fatigue and feeling weak.

Some medical research shows that it is likely to be ineffective for high cholesterol or for periodontal disease or for improving athletic performance.

There is evidence that exists that CoQ10 may be effective for supporting heart health, high blood pressure, Parkinson’s disease, migraine headaches, muscular dystrophy and other inherited muscle weakness disorders, strengthening the immune system of people with HIV/AIDS and preventing complications of blood vessels after heart bypass surgery.

The normal dosage of CoQ10 is between 100 and 200 mg daily. Most serious side effects were apparent in people who were taking elevated dosages of 600 to 1200 mg daily, and people taking 300 mg daily experienced the mild side effects such as nausea and rashes.

Supplements may affect people differently, so when taking CoQ10 it is advisable to consult with a physician to ensure the right dosage for the right condition is being consumed.