15(S)-15-methyl PGD2 is a metabolically stable synthetic analog of PGD2. In contrast to PGD2, 15(S)-15-methyl PGD2 induces vasoconstriction and increases systemic blood pressure with much reduced inhibitory activity on ADP-induced platelet aggregation.{1139} It also exhibits strong antifertility activity in hamsters (200-fold more potent than PGD2).{1139}