Tetranor-PGFM, the principal urinary metabolite of PGF2α, is excreted at rates of 7-13 µg per day in healthy females and 11-59 µg per 24 hours in healthy males. During pregnancy, female urinary levels of tetranor-PGFM increase 2 to 5-fold, returning to normal shortly after childbirth.
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.