Extra virgin olive oil is considered the most suitable for healthy diets and for preventing cardiovascular disease. Its production requires strict quality control, from cultivation to distribution, to preserve its bioactive compounds. However, insufficient production compared to demand favors adulteration, which compromises authenticity and the benefits described on the label. Therefore, the action of regulatory agencies is essential, as is compliance with ANVISA standards, according to RDC No. 481/2021. In this study, peroxide index analyses were performed on seven brands of extra virgin olive oil. The results revealed that one of the brands analyzed does not meet the standards established by Brazilian legislation, indicating possible degradation of the sample.