Both idebenone and idebenol are localized near the lipid-water interface of the membrane and increase its fluidity

Victoria Gómez-Murcia, Alejandro Torrecillas, Ana M. de Godos, Senena Corbalán-García, Juan C. Gómez-Fernández, Biochimica et Biophysica Acta (BBA) - Biomembranes, Volume 1858, Issue 6, June 2016, Pages 1071-1081, ISSN 0005-2736, doi:10.1016/j.bbamem.2016.02.034.

"Idebenone is an interesting drug but care should be taken in calling it a coenzyme Q analogue."

Idebenone is sometimes assumed to be an analog of ubiquinone, although their way of interaction with the components of the electron transport chain in mitochondria differs. Whereas ubiquinone-10 carries electrons from complex I and complex II to complex III, idebenone receives electrons from complex I. idebenone shares with ubiquinone the same quinone group, it might also be expected to act as a potent antioxidant, although other studies do not exclude the idea that idebenone may detoxify ROS in a different way to ubiquinone. Since idebenone and idebenol have similar locations, this may explain why this pair does not play exactly the same role as the couple ubiquinone-10/ubiquinol-10 in the mitochondria.

 Both idebenone and idebenol are localized near the lipid-water interface of the membrane and increase its fluidity