1-[(2S)-2-(dimethylamino)-3-(4-hydroxyphenyl)propyl]-3-[(2S)-1-(thiophen-3-yl)propan-2-yl]urea

PZM21 is a novel μ-opioid receptor (MOPr) ligand that has been reported to induce minimal arrestin recruitment and be devoid of the respiratory depressant effects characteristic of classical μ-opioid ligands such as morphine. It is an experimental opioid analgesic agent used in research.