Updated project metadata. Alzheimer's disease (AD) is a chronic neurodegenerative disorder, accounting for up to 75 % of all dementia cases. Although the basis of AD etiology remains unknown, oxidative stress constitutes a major driver given its intimate association, specially at prodromic stages of the disease. In this line, Ubiquinol, the reduced form of coenzyme Q10, is a well-known neuroprotective antioxidant and has demonstrated significant effects in oxidative responses of β-Amyloid aggregation, internalization, and apoptosis-induced neurodegeneration. However, full extent of Ubiquinol effects in the context of AD is not yet known in detail. In this study, we designed a new methodology based on MALDI MSI for evaluating the peptide profile of the 3xTg-AD mice model fed a Ubiquinol-supplemented diet. By adopting functional analysis tools, we observed differential functional profile in hippocampus and cortex levels after 4- or 10-m o supplementation. Therefore, we also identified ACAD9, XPO1 and EIF3A as potential protein references for the diagnosis of AD at early/late stages.