3-МФ

триметилфентанил (3-МФ)
(самый ядовитый наркотик, в просторечии известен как "белый китаец")
хим. trimethylfentanyl (trimethylphentanyl)

I haven't read all of the thread, but a month ago or so they said on the news that a drug called "krokodil" (trimethylfentanyl) was spreading from Russia and Eastern Europe, it was supposedly 1000 times stronger than heroin.