Coenzyme Q₁₀ (CoQ₁₀) is a naturally occurring quinone found throughout the body in cell membranes, primarily in mitochondrial membranes, with highest concentrations in the heart, lungs, liver, kidneys, spleen, pancreas, and adrenal glands. It is a component of the electron transport chain and participates in aerobic cellular respiration, generating energy in the form of ATP. In its reduced form, CoQ₁₀ acts as an antioxidant, preventing the formation of reactive oxygen species. CoQ₁₀ deficiencies have been associated with heart failure, hypertension, parkinsonism, mitochondrial encephalomyopathies, and other chronic diseases

Coenzyme Q10 is an electron transport chain component of the mitochondria, which assists proton and electron transfer across the inner mitochondrial membrane. Studies indicate that Coenzyme Q10 can protect human endothelial cells from oxidative damage by modulating the nitric oxide pathway. In addition, Coenzyme Q10 inhibits LDL oxidation, a major process in the development of atherosclerosis. Coenzyme Q10 is known to suppress the down regulation of NOS3 (endothelial nitric oxide synthase, eNOS) and up-regulation of NOS2 (inducible nitric oxide synthase, iNOS). As a result of its ability to bind Ca²⁺, Coenzyme Q10 can transport this cation across artificial biomimetic membranes.

Coenzyme Q10 is a naturally occurring benzoquinone important in electron transport in mitochondrial membranes. Coenzyme Q10 functions as an endogenous antioxidant; deficiencies of this enzyme have been observed in patients with many different types of cancer and limited studies have suggested that coenzyme Q10 may induce tumor regression in patients with breast cancer. This agent may have immunostimulatory effects. 

It is used as a component of electron transport chain and in aerobic cellular respiration, Coenzyme Q10 can protect human endothelial cells from oxidative damage by modulating the nitric oxide pathway. In addition, Coenzyme Q10 inhibits LDL oxidation, a major process in the development of atherosclerosis. Coenzyme Q10 is known to suppress the down regulation of NOS and up-regulation of NOS2. As a result of its ability to bind Ca2+, Coenzyme Q10 can transport this cation across artificial biomimetic membranes.