Polyestriol phosphate

PE3P has been used at a dosage of 40 to 80 mg by intramuscular injection once every 4 to 8 weeks in menopausal hormone therapy.^[13][10]

PE3P has been available in the form of ampoules containing 50 to 80 mg in 1 or 2 mL aqueous solution.^[13][14][15]

PE3P is similar to polyestradiol phosphate (PEP), and is, likewise, an estrogen ester – specifically, an ester and prodrug of estriol – in the form of a polymer with phosphate linkers.^[2][4][5][9] When adjusted for differences in molecular weight, PE3P contains the equivalent of about 80% of the amount of estriol.^[16] As such, 40 mg PE3P corresponds to about 32 mg estriol.^[16] Doses of PE3P of 10 mg or more have an extended duration of action.^[17] A single intramuscular injection of 80 mg PE3P has a duration of about 1 month and of 80 mg about 2 months.^[5][14]

The effects of PE3P on the vagina, uterus, pregnancy, prostate gland, coagulation, and fibrinolysis, as well as on mammary and endometrial cancer risk, have been studied.^{[18][19][20][21][22][23][24][25][16]} The endometrial proliferation dose of PE3P over 14 days in women is 40 to 60 mg by intramuscular injection.^[14]

PE3P is a water-soluble polymer of estriol with phosphoric acid.^[17]

PE3P was developed by the Swedish pharmaceutical company Leo Läkemedel AB in the 1960s.^[2][9][17] It was introduced for medical use by 1968.^[26][27]

PE3P was marketed under brand names including Gynäsan, Klimadurin, and Triodurin.^{[6][13][14][15][28]}

PE3P was marketed in Germany and Spain.^[14][29]

• Estriol phosphate
• Polytestosterone phloretin phosphate
• Polydiethylstilbestrol phosphate