According to the WHO forecast, the number of patients with diabetes mellitus is expected to increase to 1.3 billion people by 2051. At the same time, we expect an increase in neurological complications of the disease, especially in polyneuropathy (DPN) and cognitive impairment (CI) are often considered as separate, independently existing complications. They can manifest at different times, at different ages, which creates certain difficulties for screening and subsequent therapy. Traditionally applied treatment standards, strict glycemic control does not allow us to talk about complete correction of manifestations and/or reducing the risk of developing DPN without CI or mild CI. In recent years, the possibilities of peptide drugs to reduce CI and chronic neuropathic pain have been actively studied. Neuropeptides of animal origin combine the functions of hormones, growth factors, neurotransmitters, ion channel ligands, and anti-inflammatory agents. The domestic drug Cortexin is one of the most promising drugs for further clinical trials.