Cathinones

β-keto amphetamines: the same skeleton with a ketone on the β carbon. Cathinone itself is the khat alkaloid and everything else here is synthetic. The ketone makes them more polar, so they enter the brain less readily than their amphetamine counterparts without ceasing to be active. This is the family the phrase bath salts was coined for, and the one where the market renames a compound faster than any register follows it.

The internal split matters more than the names do. Ring-substituted members such as mephedrone, 3-MMC and 4-MEC release serotonin alongside dopamine; the pyrrolidinophenones — α-PVP, α-PHP, α-PiHP — are close to pure dopamine reuptake blockers, long-acting, and associated with compulsive redosing, sleeplessness and stimulant psychosis. β-keto entactogens such as methylone are filed under Entactogens. Hyperthermia and cardiovascular collapse are the class emergencies.