Deltorphin 2, specifically [D-Ala2]-Deltorphin II, is primarily utilized in research settings for its potent and selective binding to delta opioid receptors. Its application is significant in neuroscience studies, where it helps in understanding the role of delta opioid receptors in pain modulation, addiction, and emotional responses. Researchers use it to explore potential therapeutic targets for managing chronic pain, as it provides insights into receptor mechanisms without the side effects associated with mu opioid receptor activation. Additionally, it is employed in pharmacological experiments to study receptor-ligand interactions and to develop new analgesic drugs with improved safety profiles. Its selectivity makes it a valuable tool in differentiating the functions of delta receptors from other opioid receptor subtypes.