Clonidine (CAS No 4205-90-7) is a pharmacologically active compound primarily researched within the neuroscience and pharmacology fields Originating as an antihypertensive agent its mechanism mainly involves acting as an agonist at the alpha-2 adrenergic receptors in the central nervous system leading to reduced sympathetic outflow and decreased blood pressure Clonidine exhibits potent activity in the nanomolar to low micromolar range in vitro demonstrating a strong affinity for its target receptors It is commonly used in various experimental applications including cell models to study receptor interactions and animal models to evaluate effects on hypertension pain and withdrawal symptoms In drug screening clonidine serves as a reference compound particularly in investigations of novel treatments for disorders like ADHD and anxiety Experimental concentrations typically depend on the specific research design