Orexin-A, also known as hypocretin-1, is a neuropeptide that plays a crucial role in regulating various physiological processes such as arousal, wakefulness, appetite, and stress response. It is produced by a group of neurons in the hypothalamus known as orexinergic neurons. Dysfunction of the orexin system has been associated with various neurological and psychiatric disorders, including narcolepsy, obesity, addiction, and anxiety disorders. Research in the field of orexin-A aims to further understand its mechanisms of action and explore its potential therapeutic applications in treating these disorders.