13,14-dihydro-15-keto PGD2 is a metabolite of PGD2 which is formed through the 15-hydroxy PGDH pathway. 13,14-dihydro-15-keto PGD2 was recently identified as a selective agonist for the CRTH2/DP2 receptor. It also inhibits ion flux in a canine colonic mucosa preparation. In humans, 13,14-dihydro-15-keto PGD2 is further metabolized to give 11β-hydroxy compounds which have also undergone β-oxidation of one or both side chains. Virtually no 13,14-dihydro-15-keto PGD2 survives intact in the urine.