‘Synthetic cannabinoids’ or, more correctly, synthetic cannabinoid receptor agonists (SCRAs), are synthetic chemicals that mimic the effects of the natural psychoactive substances found in cannabis. ‘Legal high’ products containing SCRAs have been sold as herbal smoking mixtures since at least 2006. Recently, new products containing SCRAs have emerged such as a ‘resin’ resembling cannabis resin and liquids suitable for use in electronic cigarettes. The products have been marketed in innovative ways and may be sold openly on the internet and in specialist ‘smoke’ shops.