Xylazine is an agonist at kappa opioid receptors and exhibits sex-specific responses to opioid antagonism.

Bedard ML, Huang XP, Murray JG, Nowlan AC, Conley SY, Mott SE, Loyack SJ, Cline CA, Clodfelter CG, Dasgupta N, Krumm B, Roth BL, McElligott ZA.

Addict Neurosci. 2024 Jun;11:100155. doi: 10.1016/j.addicn.2024.100155. Epub 2024 May 3. PMID: 39086495; PMCID: PMC11290297.