Ethcathinone, also known as ethylpropion or ETH-CAT, is a stimulant drug of the phenethylamine, amphetamine, and cathinone chemical classes. It is an active metabolite of the prodrug diethylcathinone and is fully responsible for its effects.

The pharmacology for ethcathinone appeared alongside other psychostimulants in a paper by Rothman and Baumann in 2006. The predominant two modes of action for ethcathinone is as a moderately active releaser of noradrenaline (EC50 = 99.3nM);however it is only a relatively weak inhibitor of dopamine reuptake (Ki = 1,014nM).

However, in contrast to diethylcathinone, ethcathinone is not universally considered to be a prodrug since (as is the case with tramadol, codeine, and MDMA) it is already active in its own right, therefore being excluded from the category by some of the more strict definitions.