Synthetic cannabinoid receptor agonists (SCRA) are chemicals that stimulate the endogenous cannabinoid receptors within the body responsible for mediating the pharmacological effects of tetrahydrocannabinol (THC), the major active ingredient of cannabis. They are sometimes referred to as synthetic cannabinoids, but this term is misleading, as some examples are not structurally related to naturally occurring cannabinoid compounds. The first examples of SCRA were created in the 1980s to research cannabinoid receptor pharmacology and to explore the therapeutic potential of drugs interacting with the cannabinoid receptor system.