Guanfacine (CAS 29110-47-2) is a synthetic organic compound with the molecular formula C₉H₉Cl₂N₃ and a molecular weight of 232.09 g/mol. It is a white to off-white crystalline powder, sparingly soluble in water. As a specialty chemical and active pharmaceutical ingredient (API), guanfacine acts as a selective alpha-2A adrenergic receptor agonist. It is primarily used in the medical field for the treatment of attention deficit hyperactivity disorder (ADHD) in children and adolescents, improving attention, reducing impulsivity, and managing hyperactivity by modulating norepinephrine levels in the brain. It is also approved for hypertension management, where it relaxes blood vessels and decreases heart rate. Off-label uses include treatment of tic disorders such as Tourette syndrome to reduce tic frequency and severity. The extended-release formulation allows once-daily dosing for better patient compliance. In research and pharmaceutical applications, it serves as an intermediate for drug synthesis and in studies on adrenergic signaling.