CoQ10 Safety

Some of the benefits of taking Coenzyme Q10 (CoQ10) include possible reduction in heart disease and cancer, which includes an antioxidant effect. But does CoQ10 have any side effects? There have been several studies performed specifically to determine its dangers in recent years. This article will examine the evidence for the side effects of CoQ10 to see if it is considered safe or not.

A double-blind placebo controlled study published in the Regulatory Toxicology & Pharmacology in 2006 concluded that CoQ10 is safe up to 900 mgs a day. All groups, including the placebo, had some symptoms. These symptoms were similar to the common cold and also included stomach problems. Since the placebo group experienced them, it seems logical to conclude that these were psychological or transitory symptoms. Another recent study concluded an even higher level of safety.

This study, published in the same journal and in the same year, concluded no ill effects up to 1200 mgs per day. The ultimate summary was that 1200 mgs is officially the "Observed Safe Level." This is good evidence for the safety of this supplement. However, not everyone recommends taking the supplement just because it is considered "safe."

In Cardiology in Review, in 2005, a research study was published confirming the safety of CoQ10 and the fact that cholesterol-lowering drugs may cause CoQ10 deficiency. However, at the conclusion of the study the researchers did not recommend supplementation with CoQ10 along with cholesterol-lowering drugs due to lack of evidence of the benefits.

So even though cholesterol drugs can cause a serious lack of CoQ10, since there are no studies confirming the benefits of taking a supplement, the researchers recommended against it.

CoQ10 is one of the safest supplements you can take, and also one of the most beneficial. It can prevent heart disease and cancer through its strong antioxidant effects, and possibly make up for the deficiency experienced in those taking cholesterol-lowering drugs. We recommend considering CoQ10 as an addition to your daily diet if you are in a high-risk category for heart attack or cancer, and especially if you are taking Lipitor or other medications for cholesterol.


Regul Toxicol Pharmacol. 2006 Apr;44(3):212-8. Epub 2006 Jan 23

Cardiology in Review. 13(2):76-79, March/April 2005

Regul Toxicol Pharmacol. 2006 Aug;45(3):282-8. Epub 2006 Jun 30br>