Bimatoprost is the Allergan trade name for 17-phenyl trinor prostaglandin F2α ethyl amide (17-phenyl trinor PGF2α ethyl amide), an F-series PG analog which has been approved for use as an ocular hypotensive drug. Oxidation of the C-15 hydroxyl group produces 15-keto-17-phenyl trinor PGF2α ethyl amide. 15-keto-17-phenyl trinor PGF2α ethyl amide is a potential metabolite of 17-phenyl trinor PGF2α ethyl amide when 17-phenyl trinor PGF2α ethyl amide is administered to intact animals. No pharmacological studies on 15-keto-17-phenyl trinor PGF2α ethyl amide have been reported.