{Reference Type}: Journal Article {Title}: Chemical tools for the opioids. {Author}: Leon Duque MA;Vallavoju N;Woo CM; {Journal}: Mol Cell Neurosci {Volume}: 125 {Issue}: 0 {Year}: 06 2023 21 {Factor}: 4.626 {DOI}: 10.1016/j.mcn.2023.103845 {Abstract}: The opioids are potent and widely used pain management medicines despite also possessing severe liabilities that have fueled the opioid crisis. The pharmacological properties of the opioids primarily derive from agonism or antagonism of the opioid receptors, but additional effects may arise from specific compounds, opioid receptors, or independent targets. The study of the opioids, their receptors, and the development of remediation strategies has benefitted from derivatization of the opioids as chemical tools. While these studies have primarily focused on the opioids in the context of the opioid receptors, these chemical tools may also play a role in delineating mechanisms that are independent of the opioid receptors. In this review, we describe recent advances in the development and applications of opioid derivatives as chemical tools and highlight opportunities for the future.