Ubiquinol, a form of Coenzyme Q10 or CoQ10 for short, is found naturally in mitochondrial cells and contributes to the body's ability to generate energy. Levels of this compound naturally decline, according to the Mayo Clinic, and CoQ10 levels can be increased with a CoQ10 supplement. The supplement form is an antioxidant, and as such may help decrease the bodily damage caused by free radicals.
Healthy Adults and CoQ10
Adult use of CoQ10 is generally considered safe and nontoxic, according to the University of Maryland Medical Center, although gastrointestinal side effects have been reported, including nausea, vomiting, loss of appetite and diarrhoea. Some adult users of CoQ10 have reported allergic reactions in the form of skin rashes. According to the National Institutes of Health (NIH), some neurological side effects have been reported with CoQ10 usage, including dizziness and greater light sensitivity in the eyes. There are reports of fatigue and flu-like symptoms from CoQ10 use, but these symptoms and others usually are mild and transient.
Diabetic Adults and CoQ10
CoQ10 may lower blood sugar levels, according to the NIH. Patients who take medications or other supplements that affect blood sugar, or who naturally have a low blood sugar condition called hypoglycaemia, should be monitored by their doctors to be sure the interaction between CoQ10 and medications does not lower blood sugar too much.
Cancer Patients and CoQ10
As a possible adjunct medication for cancer patients, CoQ10 has an interesting track record, according to the National Cancer Institute (NCI). CoQ10 side effects in cancer patients tend to be the same as in healthy people--G.I. upset, neurological reactions, fatigue--but anecdotal evidence suggests some positive CoQ10 effects for this population, including an extension of life for patients with pancreatic, lung, colon and other cancers when the supplement was administered with radiation and chemotherapy. The NCI says researchers continue to study how CoQ10 might work in conjunction with traditional cancer therapies.
Patients Taking Medications
Another set of CoQ10 side effects pertains specifically to patients taking prescription medications. When used with Coumadin, a blood-thinning agent, CoQ10 might lead to a decrease in the medication's ability to prevent blood clots, according to the Linus Pauling Institute. And one study concluded that thyroid hormone levels might be affected by CoQ10, according to the NIH, which would have implications for patients taking thyroid hormone replacement medication.
Pregnant Women, Children and CoQ10
Despite CoQ10's generally safe profile, the Linus Pauling Institute and the University of Maryland Medical Center both discourage its use for pregnant women, saying not enough studies have been done to know what side effects might occur during pregnancy. Also, children should not be treated with CoQ10 unless instructed by a paediatrician.