p-Hydroxyamphetamine (4-hydroxyamphetamine, α-methyltyramine) is a drug that stimulates the sympathetic nervous system. When used in eye drops, it dilates the pupil. It is sold in combination with tropicamide under the brand name Paremyd. It occurs as a metabolite of amphetamine. Once thought to be a human invention, p-hydroxyamphetamine is now known to occur as an alkaloid in plants including Acacia berlandieri.