There have been no reports of significant adverse side effects of oral coenzyme Q10 supplementation at doses as high as 1,200 mg/day for up to 16 months (39) and 600 mg/day for up to 30 months (45).

 

Some people have experienced gastrointestinal symptoms (e.g., nausea, diarrhea, appetite suppression, and heartburn), which may be minimized if daily doses higher than 100 mg are divided into two or three daily doses.

 

Because controlled safety studies in pregnant and breast-feeding women are not available, the use of coenzyme Q10 supplements by pregnant or lactating women should be avoided (63).

 

Tolerable upper intake levels

Presently, no tolerable upper intake level (UL) has been set for coenzyme Q10.

 

Drug interactions

Please note:

Because of the potential for interactions, dietary supplements should not be taken with medication without first talking to an experienced healthcare provider.