the drug that exceeds the recreational categories
A substance even just the accidental-synthesis of which sent the Sandoz chemist into early retirement and serious unblinking wall-watching, the incredibly potent DMZ has a popular-lay-chemical-underground reputation as the single grimmest thing ever conceived in a tube.
Context
The drug defined entirely by an ominousness that outruns pleasure: it broke its own accidental discoverer into retirement and wall-watching, carries a reputation as the grimmest thing ever made, and is nearly unobtainable. "Recreational" is the wrong word for a compound whose defining anecdotes are all catastrophe — the appetite here has left the category of fun and entered something closer to daring the abyss.