Planet Money explains in great detail, with several of the scientific originators speaking on the show. [Should appear in the list there for re-view, in a few days; look for "Synthetic Reefer Madness".

Synthetic Reefer Madness

The business of getting people high used to require fields of poppies or marijuana, and the farmers to farm them. Over the last two decades, a new generation of potent synthetic drugs has revolutionized the illicit drug trade. These drugs are cheap, easy to make in factories, and difficult to regulate. Now, it's possible to become a kingpin with little more than an internet connection and an email address for a chemical plant in China. Today the show looks at one synthetic drug — Spice — and tell the story of how it helped unleash a revolution.

tl;dr ... look to tens of thousands new deaths as this (now and next too) out-of-control $$$-making machinery; it just won't be intimidated by merely adding new formulae to the already overloaded data-dumps behind each week's New Laws.

{{sigh}}

It ain't Easy Being (stoned)-Green. You'd have to be nutso (having heard just this program) getting Any of this stuff except maybe from a Toxicology-specialist-buddy. Most shall never hear this npr-episode and bloody well won't be given a link==that's Bizness-Drumpf-style. These bastards,, like Drumpf Don't Care about their 'base' (as in free- or politically), never mind [Hah! ... -vs- Dollars] morally.

RIP: those who are about to die from a lab-error or dosage off by n-orders-of-magnitude :-/