Methcathinone (α-methylamino-propiophenone or ephedrone) is a psychoactive stimulant, sometimes used as a recreational drug and considered addictive. It is usually snorted, but can be smoked, injected, or taken orally. Methcathinone is currently a DEA Schedule I controlled substance in the United States.

The C=O bond at the R_β-position (directly right of the benzene ring) is slightly polar, and as a result the drug does not cross the lipid blood–brain barrier quite as well as amphetamine. Nevertheless, it is a potent CNS stimulant and dopamine reuptake inhibitor. Chronic high dosage use may result in acute mental confusion ranging from mild paranoia to psychosis. These symptoms typically disappear quickly if use is stopped.

Unlike methamphetamine, methcathinone is not legal under any circumstances in the US due to its classification as a Schedule I substance. Conversely, methamphetamine has certain approved medical uses such as treatment of morbid obesity, narcolepsy and ADHD.

Methcathinone was first synthesized in 1928 in the United States and finally patented by Parke Davis in 1957. It was used in the Soviet Union during the 1930s and 1940s as an anti-depressant (under the name Эфедрон — ephedrone). Since the 1960s, methcathinone has been used as a recreational drug in the (former) Soviet Union.