"NPOs have larger μ-opioid receptor activation than morphine and fentanyl, that has Formerly been shown by an in vitro study which pharmacologically evaluated 10 nitazenes applying 2 cell-based β-arrestin2/mini-Gi recruitment assays monitoring μ-opioid receptor activation. Metonitazene is an analgesic drug linked to etonitazene, which was very first reported in 1957, https://wodirectory.com/listings12892326/not-known-details-about-metonitazene-for-sale-in-copyright