The Laundry List

Oftentimes when you see an advertisement for a drug or supplement, a laundry list of potential side effects is listed quickly after. CoQ10 is no different, as nausea, vomiting, upset stomach, heartburn, diarrhea, appetite loss, insomnia, headache, dizziness, irritability, fatigue and flu-like ailments have all been reported [source: Mayo Clinic]. Thankfully, they are generally rather mild and short lasting.

CoQ10 Side Effects

­Even though CoQ10 is a supplement and occurs naturally in your body, it doesn't mean that it's side effect free. However, most CoQ10 side effects are mild. Some people may experience allergies to increased CoQ10. There have been some reports of rashes and itching.

Other side effects include a lowering of blood sugar within the body. This is particularly a concern for those with diabetes or hypoglycemia [source: Mayo Clinic]. In addition, if you're taking another medicine to regulate blood sugar levels, tell your doctor.

CoQ10 may decrease blood pressure -- which is potentially a great benefit to some, but those with low blood pressure, or those who are already on medication to regulate their blood pressures should exercise caution before embarking on a CoQ10 supplement regimen.

Be sure to inform your doctor of any medicine, prescription or otherwise, that you are taking, no matter what you're taking them for. You never know how supplements may react with other drugs, or what effect they can have on your body. In addition, those who are pregnant or nursing should not take CoQ10 as the effects have not yet been studied.

If you have periodontal issues -- gum disease -- you might find CoQ10 could help. But do you have to start a nightly ritual of eating beef hearts every evening to help? Read on to discover the link between your gums and CoQ10 supplements.