Abstract: Electrochemical methods, preferably the Kolbe coupling reaction, are utilized to create intramolecularly bridged peptides, segments or peptide isosteres which are conformationally restricted and preferably, biologically active. Preferably, the peptide analogues contain methylene groups bridging particular amino acid side chains. Analogues of a variety of peptide hormones, including insulin, insulin-like growth factors, somatostatin, melanocyte stimulating hormone, and the like are prepared by the above methods. Such peptides are useful as agonists or antagonists for treatment of diseases associated with deficiency of the hormone or dysregulation of hormone activity, as well as for mechanistic studies to understand the interactions between peptide hormones and cells.