Some of it, like Gold Spice iirc, actually has a compound called JWH-018, which is a synthetic (i.e. made in a lab) cannabinoid. You can actually buy JWH-018 and make your own "legal" bud, and most of the people on here seem to think that JWH is pretty comparable to THC. You'll never see me touching that synthetic shit but different tokes for different folks I guess. Also notable is that Darwin's Headstash shit, that, if I understand correctly, does contain JWH-018 and works pretty well. There's also some sort of deal going where you can get like a half gram for free so if I was looking for legal buds I'd probably start there.