The Royal College of Nursing (RCN) has launched an updated edition of its UK guidance for nurses entitled ‘Advanced preparation of insulin syringes for adult patients to administer at home’ (RCN 2015). The RCN views the practice of pre-loading insulin necessary for the small minority of patients unable to use insulin pen devices, but this should only be considered after all other options have been exhausted because there are legal and safety complexities associated with this practice about which registered nurses must be aware. This article will outline those issues to assure vicarious liability protection from the nurse’s employer before undertaking this practice. It will also provide an overview of the framework requirements and necessary inclusions for a ‘best practice policy’, as well as outline the RCN Diabetes Nursing Forum recommendations.