The potential protective effects of coenzyme Q10 against COVID-19: CoQ10 is an essential co-factor in electron transport chain of the phosphorylation oxidative system. Because of its lipophilic anti-oxidant power, it has potential ability for regenerating the VitE and VitC. Moreover, the anti-angiotensin 2 effect of CoQ10 improve the RAS activity which is upregulated in COVID-19. The anti-apoptotic, immunomodulatory, and anti-inflammatory effects of CoQ10 have been also confirmed through reducing TNF-a, IL-6, and CRP. The cardiovascular protective effects of CoQ10 have been also determined, such as improving viral myocarditis and using in drug induced cardiotoxicity. Moreover, CoQ10 has some protective effects in CNS. It can pass easily through BBB, reduce oxidative stress, and modulate the immunologic reaction. BBB: Brain blood barrier.