Following media attention on children with refractory epilepsies reportedly deriving benefit from cannabis-based medicinal products (CBMPs), the UK government changed the law in 2018 so that CBMPs could be legally prescribed. Subsequently, a pure cannabidiol (CBD) product has been licensed for two epilepsy syndromes. However, despite pressure from campaign groups and allied politicians, almost no children have received unlicensed CBMPs under the UK NHS. This review explores the science behind CBMPs in paediatric epilepsies and highlights the areas that warrant further research. It identifies a lack of level I evidence for efficacy and safety as, currently, the major obstacle to prescribing. Unlicensed medicines are often used in paediatrics but almost all are used 'off-label', with supporting evidence of efficacy and safety derived either from other age-groups or from disease conditions. CBMPs, except for pure CBD, are unique in that they are currently both unlicensed and fall outside the 'off-label' category. The review acknowledges the treatment gap in refractory epilepsies and the potential use of CBMPs. However, it argues against exceptionally circumventing the usual standard of evidence required by regulatory prescribing authorities and warns against allowing vulnerable children to become the 'trojan horse' for deregulation of the commercial cannabis market.