"Synthetic cannabinoids are functionally similar to delta9-tetrahydrocannabinol (THC), the psychoactive principle of cannabis, and bind to the same cannabinoid receptors in the brain and peripheral organs."
Fattore, Liana, and Walter Fratta. “Beyond THC: The New Generation of Cannabinoid Designer Drugs.” Frontiers in behavioral neuroscience vol. 5 60. 21 Sep. 2011, doi:10.3389/fnbeh.2011.00060