Pseudoephedrine is a drug that can be used as a nasal decongestant or a stimulant.

Pseudoephedrine works primarily on the adrenergic receptor system. Vasoconstriction is caused by pseudoephedrine acting on the α- and β2-adrenergic receptor, relaxing the smooth muscle of the bronchi and vasoconstriction.

Common side effects of pseudoephedrine include insomnia, anxiety, hypertension and urinary retention.