Guanfacine hydrochloride (CAS 29110-47-2) is the hydrochloride salt of guanfacine, a selective α_2A-adrenergic receptor agonist. It serves as an active pharmaceutical ingredient (API) primarily in medications for attention deficit hyperactivity disorder (ADHD) in children and adolescents, and for hypertension in adults. It modulates noradrenergic activity in the prefrontal cortex to improve attention, reduce impulsivity, and hyperactivity, while also reducing blood pressure via central sympatholytic effects.

Chemical Properties:
- Molecular Formula: C₉H₁₁Cl₂N₃O · HCl
- Molecular Weight: 282.57 g/mol
- Appearance: Crystals or powder (white to off-white)

This high-purity (≥99%) reference standard is ideal for pharmaceutical research, analytical development, quality control, and synthetic applications.