Supplementation with CoQ10 is generally considered safe and well-tolerated, even at high dosages (1,200 mg per day)[1] and for durations up to 12 months.[1]
Regarding potential interactions, there is mixed clinical evidence that CoQ10 may interact with warfarin.[2][3][4] Additionally, animal studies suggest a potential interaction between CoQ10 and theophylline (a drug used for asthma and chronic obstructive pulmonary disease).[5]