Coenzyme Q10 (Co Q10) is a compound your body produces naturally to support cell function. While generally safe, it can cause side effects, especially at high doses. Most are mild, but serious reactions are possible.
Co Q10 acts as an antioxidant and plays a key role in energy production within cells. It's often taken as a supplement to support heart health, reduce fatigue, or slow aging. The body absorbs it best in oil-based forms, such as softgels.
| Type | Common Dose | Absorption Rate |
|---|---|---|
| Ubiquinone | 100-300 mg | Moderate |
| Ubiquinol | 100-200 mg | High |
Ubiquinol is the reduced, more active form of Co Q10, making it easier for the body to absorb. However, both forms can cause side effects if taken in excess.
The most frequently reported side effects of Co Q10 are mild and may include:
These typically occur when starting a new supplement regimen or increasing the dose too quickly. They usually subside as the body adjusts.
Rarely, Co Q10 can cause more severe reactions, including:
A 2018 study published in the Journal of Clinical Medicine found that high doses of Co Q10 (over 300 mg per day) were linked to increased liver enzymes, indicating potential liver strain. Always consult a doctor before taking high doses.
Certain groups should exercise caution when taking Co Q10:
If you fall into one of these categories, discuss Co Q10 with your healthcare provider before starting supplementation.
To reduce the risk of side effects, follow these guidelines:
I once experienced mild nausea when taking Co Q10 for the first time. Reducing my dose and taking it with breakfast helped eliminate the issue.
Contact your doctor if you experience any of the following while taking Co Q10: