LIH383 is a peptide agonist specifically designed to activate the chemokine (C-X-C motif) receptor 7 (CXCR7), which functions both as a chemokine and an opioid peptide scavenger receptor. Demonstrating a high selectivity, LIH383 activates CXCR7 with an effective concentration (EC50) of 0.61 nM, showing significantly lower affinity towards μ-, δ-, and κ-opioid receptors, as well as the nociceptin opioid peptide (NOP) receptor, even at concentrations of 3 µM in β-arrestin recruitment assays. Furthermore, at a concentration of 3 µM, LIH383 effectively inhibits the uptake of opioid peptides by CXCR7, a process normally induced by dynorphin A, a non-selective opioid receptor agonist, in U87-ACKR3 cells.