Sibutramine hydrochloride is among the most prescribed satiety inducer for obesity control and it has also been added, in a fraudulent way, in proteinrich food complement for athletes. There is no analytical method for sibutramine described in the official literature. The goal of this work is to develop and validate electroanalytical methods for the determination of sibutramine in pharmaceuticals and in protein-rich food complements. Differential pulse voltammetry (DPV) and square wave voltammetry (SWV) were the techniques employed. The influence of electrochemical parameters was studied in order to select the best working conditions such as supporting electrolyte (Mcllvaine buffer), pH (4.0), scan rate (40 mV s(-1) for DPV and 240 mV s(-1) for SWV) and pulse amplitude (50 mV). The pre-concentration of sibutramine in the working electrode (mercury drop) was not possible. The electrochemical behavior in the mercury electrode was also investigated using cyclic voltammetry. The reduction of sibutramine is probably reversible and involves of 1 proton and 1 electron. The peak potential of sibutramine is about - 100 mV (Ag/AgCl3 mol L(-1)). In the validation process, the linear range of the analytical response (from the limit of quantification to 33.3 mg L-1, in both methods), the limit of detection (0.6 for DPV and 0.4 mg L(-1) for SWV) and the limit of quantification (1.8 for DPV and 1.1 mg L(-1) for SWV) were evaluated. Satisfactory precision was achieved. Recovery tests produced results of 90.4% for both methods. These results were compared with the ones achieved by HPLC and no significant statistical difference was found between them.