Brain-derived neurotrophic factor (BDNF) plays a crucial role in neuronal survival, growth, and plasticity, as well as in energy metabolism and glucose homeostasis. BDNF binds to its high-affinity receptor, TrkB, which activates signal transduction cascades (IRS1/2, PI3K, Akt), leading to the production of proteins involved in β-cell survival. BDNF and insulin-like growth factor-1 share similar downstream signaling mechanisms, including p-CAMK and MAPK, which increase the expression of pro-survival genes. BDNF regulates glucose and energy metabolism, preventing β-cell exhaustion. Reduced BDNF levels are associated with neurodegenerative diseases such as Parkinson's, Alzheimer's, multiple sclerosis, and Huntington's disease. BDNF may be useful in preventing and managing diseases including diabetes mellitus. The article also discusses the structure, origin, and mechanism of action of BDNF, its receptors, and the signaling pathways it activates. Additionally, it explores the role of BDNF in neurogenesis, synaptic plasticity, cardiac and endothelial cell functions, inflammation, lipid metabolism, and neurological disorders. The clinical implications of BDNF, including its potential as a therapeutic agent for neurodegenerative and metabolic diseases, are highlighted.Brain-derived neurotrophic factor (BDNF) plays a crucial role in neuronal survival, growth, and plasticity, as well as in energy metabolism and glucose homeostasis. BDNF binds to its high-affinity receptor, TrkB, which activates signal transduction cascades (IRS1/2, PI3K, Akt), leading to the production of proteins involved in β-cell survival. BDNF and insulin-like growth factor-1 share similar downstream signaling mechanisms, including p-CAMK and MAPK, which increase the expression of pro-survival genes. BDNF regulates glucose and energy metabolism, preventing β-cell exhaustion. Reduced BDNF levels are associated with neurodegenerative diseases such as Parkinson's, Alzheimer's, multiple sclerosis, and Huntington's disease. BDNF may be useful in preventing and managing diseases including diabetes mellitus. The article also discusses the structure, origin, and mechanism of action of BDNF, its receptors, and the signaling pathways it activates. Additionally, it explores the role of BDNF in neurogenesis, synaptic plasticity, cardiac and endothelial cell functions, inflammation, lipid metabolism, and neurological disorders. The clinical implications of BDNF, including its potential as a therapeutic agent for neurodegenerative and metabolic diseases, are highlighted.