Mechanism

Progesterone

Steroid hormone produced by the corpus luteum, adrenal glands, and placenta. It prepares the endometrium for pregnancy, sustains gestation, and in the brain it has a neuroactive metabolite (allopregnanolone) that acts on GABA-A receptors as an endogenous anxiolytic.

Effect by goal · level of evidence

Menstrual cycle

regulates Very high physiology (A)

Cyclical regulation

Luteal phase of the cycle: prepares the endometrium, maintains pregnancy if implantation occurs. Its drop at the end of the cycle triggers menstruation and, in some women, PMS.

Pregnancy

sustains Very high physiology (AAA)

Pregnancy support

Without progesterone there is no pregnancy. Supplementation in luteal insufficiency or assisted reproduction techniques is standard of care.

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Anxiety and PMS (via allopregnanolone)

modulates Moderate physiology (A)

Endogenous anxiolytic

Allopregnanolone (a metabolite) is a potent GABA-A agonist. Its cyclical fluctuation explains part of premenstrual and postpartum anxiety. Brexanolone (synthetic allopregnanolone) is approved for severe postpartum depression.

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Sleep

improves Moderate RCT (AA)

Menopausal insomnia target

Oral progesterone 100-200 mg at bedtime improves sleep in perimenopause. Effect via allopregnanolone on GABA. Alternative to benzodiazepines in this group.

View the study (systematic review) →

Information, not medical advice. Scientific evidence reflects the quality of the studies.