Guanfacine-¹³C,d₅ hydrochloride is the deuterium and ¹³C labeled Guanfacine hydrochloride (HY-17416). Guanfacine hydrochloride is an orally active noradrenergic α2A agonist and has high selective for the α2A receptor subtype. Guanfacine has effects in producing hypotension and sedation. Guanfacine can be used for the research of a variety of prefrontal cortex (PFC) cognitive disorders, including tourette’s syndrome and attention deficit hyperactivity disorder (ADHD)^[1][2][3].