ASP 8477 is an orally active and selective fatty acid amide hydrolase ( FAAH ) inhibitor with IC 50 values of 3.99, 1.65, and 57.3 nM for human FAAH-1 , FAAH-1 (P129T) , and FAAH-2 , respectively. ASP 8477 has central nervous system activity and can be used in analgesia research.