Oral micronized progesterone

Area of Science:

• Endocrinology
• Pharmacology
• Gynecology

Background:

• Unopposed estrogen therapy increases risks of endometrial hyperplasia and adenocarcinoma.
• Synthetic progestins like norethisterone and medroxyprogesterone acetate have associated metabolic and vascular side effects.
• Natural progesterone is biologically identical to endogenous hormones.

Purpose of the Study:

• To review the rationale for using oral micronized progesterone over synthetic progestins for key indications.
• To evaluate the safety and efficacy of oral micronized progesterone in endometrial protection.
• To compare oral micronized progesterone with synthetic progestins in managing estrogen therapy side effects.

Main Methods:

• Review of comparative studies and clinical trial data.
• Analysis of pharmacokinetic data, including bioavailability and variability.
• Examination of endometrial protection and side effect profiles.

Main Results:

• Oral micronized progesterone demonstrates comparable bioavailability and inter/intra-individual variability to synthetic progestins.
• It provides effective long-term endometrial protection with a favorable side effect profile, mainly mild drowsiness.
• Comparative studies indicate synthetic progestins' side effects are minimized or eliminated with natural progesterone.

Conclusions:

• Oral micronized progesterone is recommended as a preferred option for opposing estrogen therapy in nonhysterectomized postmenopausal women.
• It offers a safer alternative to synthetic progestins, mitigating risks of endometrial hyperplasia and adenocarcinoma.
• The oral formulation circumvents inconvenience, providing a well-tolerated and effective therapeutic option.