America's Compounding center says the following about idebenone:
"Idebenone is a synthetic product similar to coenzyme Q10 (CoQ10) which is primarily used for its antioxidant effects. The effects of idebenone are being investigated in patients with Alzheiner's disease, optic nerve problems, a type of heart failure known as Fredreich's ataxia, and mitochonrial disease. Patients most commonly receive doses of 90-120mg of idebenone by mouth daily, but doses up to 300mg daily have been used. Side effects associated with the use of idebenone include stomach upset, nausea, vomiting, diarrhea, headache, dizziness, and confusion."