Procaterol hydrochloride is a synthetic, selective β2-adrenergic receptor agonist. It is a white to off-white crystalline powder, typically used as the active pharmaceutical ingredient (API). Its chemical structure is based on a catecholamine scaffold, featuring a hydroxyquinoline moiety. Its primary and most significant application is in the treatment of respiratory diseases, particularly bronchial asthma, chronic bronchitis, and emphysema. It acts by relaxing bronchial smooth muscle, leading to bronchodilation and improved airflow. It is formulated for oral administration. Additionally, due to its action on β2-adrenoreceptors, it has been investigated for potential use in neurological conditions, such as enhancing cognitive function and as a potential therapeutic agent for neurodegenerative diseases, linking it to the nervous system drug category. Procaterol hydrochloride is known for its potent and long-lasting bronchodilatory effects with relatively fewer cardiovascular side effects compared to non-selective β-agonists. It is a prescription drug and its use is subject to medical supervision.