"‘Spice’ and other ‘herbal’ products are often referred to as ‘legal highs’ or ‘herbal highs’, in reference to their legal status and purported natural herbal make-up (McLachlan, 2009; Lindigkeit et al., 2009; Zimmermann et al., 2009). However, albeit not controlled, it appears that most of the ingredients listed on the packaging are actually not present in the ‘Spice’ products and it is seems likely that the psychoactive effects reported are most probably due to added synthetic cannabinoids, which are not shown on the label. There is no evidence that JWH, CP and/or HU [three chemically distinct groups of synthetic cannabinoids] compounds are present in all ‘Spice’ products or even batches of the same product. Different amounts or combinations of these substances seem to have been used in different ‘Spice’ products to produce cannabis-like effects. It is possible that substances from these or other chemical groups with a cannabinoid agonist or other pharmacological activity could be added to any herbal mixture (17) (Griffiths et al., 2009).
"The emergence of new, smokable herbal products laced with synthetic cannabinoids can also be seen as a significant new development in the field of so-called ‘designer drugs’. With the appearance, for the first time, of new synthetic cannabinoids, it can be anticipated that the concept of ‘designer drugs’ being almost exclusively linked to the large series of compounds with phenethylamine and tryptamine nucleus will change significantly (18). There are more than 100 known compounds with cannabinoid receptor activity and it can be assumed that further such substances from different chemical groups will appear (with direct or indirect stimulation of CB1 receptors)."
"Understanding the 'Spice' phenomenon," European Monitoring Centre for Drugs and Drug Addiction (Luxembourg: Office for Official Publications of the European Communities, 2009), p. 21.