Definition
Progesterone is a steroid hormone essential to reproduction and with significant effects on brain, sleep, mood, and inflammation — partly through its neurosteroid metabolite allopregnanolone.
Why it matters
Progesterone is more than a fertility hormone. Its effects on the nervous system are meaningful and often undertaught.
The Science
Allopregnanolone is a potent positive modulator of GABA-A receptors, producing sedative and anxiolytic effects. Progesterone fluctuations across cycle, pregnancy, postpartum, and perimenopause influence mood and sleep in documented ways. Brexanolone (an allopregnanolone analog) is approved for postpartum depression.
The NSI Perspective
NSI treats progesterone dynamics as legitimate clinical territory, not vague “hormone” complaints.
Clinical Implications
PMDD, perimenopausal mood, and postpartum depression all involve progesterone-linked biology.
Practical Application
If certain days of your cycle reliably darken your mood or fragment your sleep, that is biology. It is not “all in your head.”
References
- 1.Schule C, Nothdurfter C, Rupprecht R. The role of allopregnanolone in depression and anxiety. Prog Neurobiol. 2014;113:79–87.