Ephedrine (/ɨˈfɛdrɪn/ or /ˈɛfɨdriːn/) is a sympathomimetic amine and substituted amphetamine commonly used as a stimulant, concentration aid, decongestant, appetite suppressant, and to treat hypotension associated with anaesthesia.Ephedrine is similar in molecular structure to the well-known drugs phenylpropanolamine and methamphetamine, as well as to the important neurotransmitter epinephrine (adrenaline).