苯丙醇胺（Phenylpropanolamine，PPA），又称去甲基麻黄素或去甲麻黄碱，分子式C₉H₁₃NO，CAS编号：14838-15-4。是一种苯乙胺类的药物。目前在美国，年轻妇女必须要有处方签才能购买这种药物，其他地区则没有限制。一种本来很常用的收鼻水药物，可以使阻塞的上呼吸道及气管变得畅通。

在香港，最普通的包装是一粒上白下绿的圆型药饼，收鼻水功效非常快，但服后会使人眼困。而在市面上比较常见而含有PPA的药物有Neozap。

Phenylpropanolamine (BAN and INN; PPA, β-hydroxyamphetamine), also known as the stereoisomers (−)-norephedrine and norpseudoephedrine, is a psychoactive drug of the phenethylamine and amphetamine chemical classes which is used as a stimulant, decongestant, and anorectic agent. It is commonly used in prescription and over-the-counter cough and cold preparations. In veterinary medicine, it is used to control urinary incontinence in dogs under trade names Propalin and Proin.