4-[1-hydroxy-2-(methylamino)ethyl]phenol, also known as metaraminol, is a synthetic sympathomimetic amine. Its chemical structure features a phenolic ring substituted with a β-hydroxyethylamine side chain containing a methylamino group. This structure is a key pharmacophore for adrenergic receptor activity. Metaraminol is primarily used as an active pharmaceutical ingredient (API) in the form of its bitartrate salt. It functions as a potent vasopressor and is clinically employed to treat hypotension, particularly in acute settings such as during anesthesia or in cases of septic shock. Its mechanism of action involves direct stimulation of α-adrenergic receptors, leading to peripheral vasoconstriction and a subsequent increase in blood pressure. It also has some β-adrenergic activity. Due to its structural role as a core building block for adrenergic agents, it is also utilized as a key synthetic intermediate in pharmaceutical research and development for the preparation of related compounds.