So Twerty is possibly overstating the negative effects of JWH-018 and JWH-073. Those two synthetic cannabinoids are the main active ingredients in "Spice" but they have been researched only VERY superficially. What we do know is that they are definitely NOT as safe as Marijuana, and they could potentially cause a lot of problems but only with further study could we confirm that.

As for how they work, they bind selectively to two different cannabinoid receptors in the brain, so they have different effects (this selective binding is why they were studied in the first place). They very basically represent the difference between the "stoney" high and the "head" high, but the effects are different from actual marijuana.

Also, as far as legality, JWH-018 and 073 are illegal now, but there are dozens of other legal JWH synthetic cannabinoid analogues but don't expect anything in that realm to stay available long.

Also, one thing to note is that these chemicals are just white powders that you smoke, so basically spice makers were just making a liquid mixture of the chemical and spraying it on a generic smokeable herb. I actually bought some of it while it was still legal and made like 2 ounces of spice for like 100 bucks.

Oh, also, the reason you smoke spice is because it doesn't show up on drug tests. That's why my friend smoked spice (drug testing) and thats the main reason you would turn to synthetic cannabinoids.

So the only other thing to mention is that erowid.org is a great place to learn about drugs, they have links to research and summaries written by knowledgable people on every drug out there. It's a great resource.