Pituitary adenylate cyclase activating polypeptide-38 (PACAP-38) plays a significant role in neuroprotection and is being investigated for its potential in treating neurodegenerative diseases such as Parkinson’s and Alzheimer’s. It modulates neuronal survival, reduces inflammation, and supports the growth and function of nerve cells. Due to its ability to regulate cerebral blood flow and protect against ischemic damage, PACAP-38 is also studied in stroke therapy. Additionally, it influences circadian rhythms, hormone secretion (including insulin regulation), and immune responses, making it relevant in endocrine, inflammatory, and metabolic disorders such as type 2 diabetes. Research is ongoing into its use as a therapeutic agent in migraine treatment, where it may help regulate pain pathways and vascular activity in the brain. It also shows promise in neural tissue repair after injury. Its broad receptor distribution in the central and peripheral nervous systems underscores its potential in developing treatments for neurological and psychiatric conditions.