Recent studies highlight the growing interest in electrochemical peptide modification, particularly the S-arylation of cysteine. Building on previous research, we present an electrochemical method for the site-selective coupling of cysteine-containing peptides with aryl halides to synthesize S-arylated peptides. Using 4-iodoanisole as the aryl halide, magnesium (Mg) as the anode, and nickel (Ni) as the cathode, this strategy was successfully applied to both short and long peptides under mild and cost-effective conditions. The simplicity of the reaction setup and the use of inexpensive materials underscore its potential as an economical alternative to traditional stapling methods. This electrochemical approach not only offers a more sustainable route to peptide modifications but also broadens their applicability in drug development and biomolecular research, paving the way for novel peptide-based therapeutics with enhanced stability and activity.