Pseudoephedrine is a member of the class of the class of phenylethanolamines that is (1S)-2-(methylamino)-1-phenylethan-1-ol in which the pro-S hydrogen at position 2 is replaced by a methyl group. It has a role as a central nervous system drug, a bronchodilator agent, a sympathomimetic agent, a xenobiotic, an anti-asthmatic drug, a vasoconstrictor agent, a plant metabolite and a nasal decongestant. It is a member of phenylethanolamines, a secondary alcohol and a secondary amino compound. It is a conjugate base of a pseudoephedrine(1+).