Lipid peroxidation has supposed as the major biochemical alteration underling oxidant-induced cell injury in stress including numerous diseases. One of the natural molecules know to prevent or retard oxidation is alpha-lipoic acid (LA) and, therefore, the lipoic acid/dihydrolipoic acid (LA/DHLA) redox couple has received considerable attention. Recent studies have highlighted the potential of free LA and DHLA as powerful metabolic antioxidants that are able to scavenge the reactive oxygen species, to recycle other antioxidants. Our aim was to investigate the beneficial effects of LA in the treatment of Italian pre-obese and obese subjects. We screened 1612 subjects for enrollment; of these, 1127 subjects (445 men and 682 women, 18-60 age) met enrolment criteria and were enrolled in the study. According to body mass index (BMI) the 53% was obese and the 43% was pre-obese. The subjects were treated for 4 month with 800 mg/day of LA. In pre-obese subject significant reduction (p<0.001) of weight (8%, both gender), BMI (2 points), blood pressure, and abdominal circumference (female 6 cm, male 7 cm) were observed. In obese subjects significant reductions (p<0.001) of weight (9%, both gender), BMI (female 3 point, male 4 point), blood pressure and abdominal circumference (female 9 cm, male 11 cm) were observed. Our study indicated that LA is an ideal antioxidant candidate for the therapy of obesity related diseases. Further clinical studies should be considered to highlight the role and efficacy of LA treatment.