Propranolol is a propanolamine that is propan-2-ol substituted by a propan-2-ylamino group at position 1 and a naphthalen-1-yloxy group at position 3. It has a role as a beta-adrenergic antagonist, an anxiolytic drug, an anti-arrhythmia drug, a vasodilator agent, an antihypertensive agent, a xenobiotic, an environmental contaminant and a human blood serum metabolite. It is a secondary amine, a propanolamine and a member of naphthalenes. It is functionally related to a 1-naphthol.