Herkinorin (Item No. 20925) is an analytical reference standard that is functionally categorized as an opioid. It is a natural neoclerodane diterpene from S. divinorum that preferentially activates the μ-opioid receptor. Unlike the peptide DAMGO , herkinorin activates μ-opioid receptors without inducing arrestin-mediated receptor internalization. Herkinorin has antinociceptive effects in rats. It has been identified as a novel psychoactive substance in multiple agitated emergency department patients screened in a non-targeted manner. This product is intended for research and forensic applications.