I have been laboring under the illusion that idebenone is a synonym for the anti-oxidant CoQ10 (coenzyme Q10). Although idebenone is a synthetic analogue of CoQ10 (a natural, vitamin-like compound), it is slightly different but in a way that has significant implications.
In certain conditions, CoQ10 can switch function from an anti-oxidant to an auto-oxidant. This means that it can produce free radicals that damage cells. Idebenone, which sometimes appears on ingredients lists as hydroxydecyl ubiquinone, does not have this risk. There are some other distinctions. Idebenone is more water soluble than CoQ10. It also has a slightly different anti-oxidant profile making it better at fighting some kinds of free radical (those that result from reduced blood flow), but less good at others.
Overall, it appears to be pretty potent. A 1% concentration outperforms the same concentration of ascorbic acid (basic vitamin C, not the strongest type) and vitamin E. One study seems to suggest that idebenone doesn't get any better in concentrations higher than 1%. Furthermore, a combination of vitamins C and A plus ferulic acid outperforms idebenone. One independent study published in the Journal of Cosmetic Dermatology, found that 0.5% concentration of idebenone reduced wrinkles by 27% over six weeks.
It is one more reason to love my Skin Image Ormedic Balancing Bio-peptide Creme. Idebenone exists in a 1% concentration in the professional Prevage range (Prevage MD) and in 0.5% in Elizabeth Arden Prevage. It is also in a number of Priori products. However, I took a look at Priori Smooth Lines with 0.5% idebenone and concluded it had too many potential irritants and a lot of standard emollients and silicones.