Purity >98%. AC-55541 is a proteinase-activated receptor 2 (PAR2) agonist that displays no activity at other PAR subtypes or at over 30 other receptors involved in nociception and inflammation. It stimulates cell proliferation, phosphatidylinositol hydrolysis, and calcium mobilization in in vitro functional assays (pEC50 s = 6.7, 5.9, and 6.6, respectively). Intrapaw administration of 3-10 mg/kg AC-55541 elicited pronociceptive activity in vivo .