Here we explore electrochemical dethiylation in processes relevant to Native Chemical Ligation (NCL). NCL's reliance on the redox active amino acid cysteine and β-mercaptamine derivatives suggests a potential role for electrochemistry. We show that the application of a 1 V potential to platinum electrodes in 0.15 M TCEP solution is sufficient to convert Cys to Ala in cyclic peptides, and to cleave the 2-mercapto-2-phenethyl class of acyl transfer auxiliary.