Obesity is the result of a higher caloric energy expenditure increasing the risk of developing diabetes and cardiovascular diseases. Citrus aurantium, has been used for weight reduction by having p-Synephrine, a compound associated with this action. The objective of this work was to evaluate the effects of commercial extract of Citrus aurantium in weight alteration in the biochemical parameters of rats induced to obesity by High fat / cafeteria diet. The animals were divided into four experimental groups: Group 1: Standard commercial feed; Group 2: standard commercial feed, and solution of commercial extract of Citrus aurantium, via gavage; Group 3: high fat/cafeteria feed. Group 4: high fat/cafeteria feed commercial extract of Citrus aurantium, via gavage. In order to maintain the same experimental conditions in all groups, the animals in groups 1 and 3, received filtered water via gavage. Tests were performed to evaluate the antioxidant capacity of commercial extract of Citrus aurantium: total phenolic compounds, DPPH and FRAP.E in the plasma of animals: FRAP in addition to analyzes of blood biochemical parameters. Results obtained with the commercial extract showed positive results, however, the antioxidant activity in plasma, was not able to alleviate oxidative stress. Significant differences were found in the values of Aspartate aminotransferase, alanine aminotransferase, VLDL cholesterol, HDL and triglycerides, however there was no reduction of weight. The commercial extract of Citrus aurantium, is important in the prevention of hepatic damage and diseases linked to elevations in the levels of VLDL and triglyceride levels, especially when this increase is associated with obesity.