• You're all caught up!

Bad Side Effects from CoQ10

author image Matthew Busse
Matthew Busse has pursued professional health and science writing since 2007, writing for national publications including "Science Magazine," "New Scientist" and "The Scientist." Busse holds a doctorate in molecular biology from the University of California-San Diego.
Bad Side Effects from CoQ10
Headache is one possible side effect of Coenzyme Q10. Photo Credit Iromaya Images/Iromaya/Getty Images


Coenzyme Q10, abbreviated CoQ10, is an enzyme that is naturally produced by the body and involved in basic cellular processes. Evidence suggests that levels of CoQ10 are decreased in patients with certain conditions, including heart disease, Parkinson's disease, cancer, diabetes, HIV/AIDS, and muscular dystrophy. Levels of CoQ10 may also decrease with age. People sometimes take CoQ10 supplements, although not enough research has been done to determine if the supplements are beneficial, according to Medline Plus. Coenzyme Q10 is generally considered safe and usually causes only minor side effects.

Upset Stomach

Bad Side Effects from CoQ10
The most common side effect caused by CoQ10 is upset stomach. Photo Credit AlexRaths/iStock/Getty Images

The most common side effect caused by CoQ10 is upset stomach, reports the University of Maryland Medical Center. Clinical trials have found that less than 1 percent of people taking CoQ10 develop mild gastrointestinal discomfort, according to an article published in the September 2005 issue of "American Family Physician." Vomiting, heartburn, loss of appetite, diarrhea and abdominal pain are also possible side effects.

Low Blood Pressure and Low Blood Sugar

Bad Side Effects from CoQ10
Low blood pressure is one of the side effects of coenzyme Q10. Photo Credit Fuse/Fuse/Getty Images

Taking coenzyme Q10 can cause blood sugar levels to decrease. Patients with diabetes or other forms of hypoglycemia should exercise caution when taking CoQ10. Lowered blood pressure may also result from coenzyme Q10, reports MedlinePlus. Patients diagnosed with low blood pressure or who are taking blood pressure medications should consult with their doctors before taking CoQ10 supplements. Reports of alterations in liver enzymes, triglycerides and cholesterol levels have also been reported. Because of these potential effects, people taking CoQ10 supplements are advised to avoid strenuous exercise, according to Medline Plus.

Headache, Dizziness, Insomnia and Flu-like Symptoms

Bad Side Effects from CoQ10
Headaches, insomnia and dizziness are other possible side effects. Photo Credit tab1962/iStock/Getty Images

Headaches are another side effect potentially caused by Coenzyme Q10, as is dizziness. People may also develop sensitivity to light. Coenzyme Q10 may cause rashes and itching of the skin in some people taking the supplement, the National Cancer Institute reports. Irritability, insomnia and fatigue are additional side effects that have been reported with CoQ10. The supplement may also cause flu-like symptoms, according to Medline Plus.

Drug Interactions

Bad Side Effects from CoQ10
Coenzyme Q10 may cause interactions with many different types of medications. Photo Credit diego_cervo/iStock/Getty Images

Coenzyme Q10 may cause interactions with many different types of medications, including drugs used to lower blood sugar levels, cholesterol or blood pressure, explains the National Cancer Institute. Insulin and the blood thinner warfarin may also interact with CoQ10. Anyone taking medications should consult with a doctor before taking coenzyme Q10 supplements.

LiveStrong Calorie Tracker
Lose Weight. Feel Great! Change your life with MyPlate by LIVESTRONG.COM
  • Gain 2 pounds per week
  • Gain 1.5 pounds per week
  • Gain 1 pound per week
  • Gain 0.5 pound per week
  • Maintain my current weight
  • Lose 0.5 pound per week
  • Lose 1 pound per week
  • Lose 1.5 pounds per week
  • Lose 2 pounds per week
  • Female
  • Male
ft. in.



Demand Media