What Is Synthetic Marijuana and Why Is It More Dangerous Than the Real Thing?

Popular Science Magazine provides a detailed but readable account of the cannabinoid-containing substances packaged as incense but sold as smokable concoctions that get you “good and high.” Trouble is, the reason they’re also labeled “not for human consumption” is that their effects are unpredictable and can be deadly.

http://www.popsci.com/science/article/2013-04/synthetic-marijuana-what-is-it?page=2