Cortagen, also known as Ala-Glu-Asp-Gly or Cortexin peptide, is a synthetic tetrapeptide derived from the naturally occurring polypeptides found in the cerebral cortex. Its structure consists of a sequence of four amino acids: alanine, glutamic acid, aspartic acid, and glycine. The synthesis of Cortagen involves standard peptide synthesis techniques, which allow for precise control over the sequence and purity of the compound. Researchers have been interested in Cortagen due to its potential nootropic and central nervous system (CNS) effects. Studies have primarily focused on its role in enhancing cognitive function, neuroprotection, and its potential therapeutic effects in neurodegenerative diseases. Observed effects include improved memory, learning, and stress resistance in various experimental models. The mechanism of action of Cortagen is not fully understood, but it is believed to involve modulation of neurotrophic factors and neurotransmitter systems. Researchers have suggested that it may influence the expression of brain-derived neurotrophic factor (BDNF) and other neuropeptides, contributing to its neuroprotective and cognitive-enhancing effects. Pharmacokinetic data on Cortagen is limited. Its half-life and bioavailability vary depending on the route of administration, with subcutaneous and intramuscular routes being the most studied. The stability of Cortagen in biological systems and its metabolic pathways remain areas of active research. Currently, Cortagen is primarily a subject of preclinical research, with limited clinical trials conducted. It is not approved as a medicinal product by major regulatory agencies, and its use is largely confined to experimental and research settings.