15 (R) -15-methyl Prostaglandin F2α

15 (R) -15-methyl PGF2α, a metabolically stable analog of PGF2α, is an inactive, prodrug PGF agonist intended for activation by gastric acid through oral administration. This transformation involves acid-catalyzed epimerization that converts 15 (R) -15-methyl PGF2α into its active counterpart, the 15 (S) -isomer. Upon conversion, the 15 (S) -isomer has been shown to induce luteolysis in rhesus monkeys following an approximately 12 mg/animal dosage, a response not observed with the 15 (R) -isomer.