Reply #4: Let me help you to understand

[jmowreader]

Synthetic marijuana is also known as "herbal incense." It is a herb--they could use oregano, and I think some of these mixtures DO--that's been sprayed with an indole compound called JWH-018, which produces an intoxication that's similar to that of marijuana.

The interest in it is, while it produces a pot-like high it is not detectable on a THC test because chemically JWH-018 looks absolutely nothing like THC or any of THC's products of metabolism so it won't show up on a piss test for pot. It will show up on a test for the JWH compounds (JWH-018 and JWH-025), and they've got these tests now.