hormone-guides

Progesterone and Sleep: Why the Luteal Phase Changes How You

Progesterone's metabolite allopregnanolone acts on GABA receptors to promote sleep. When progesterone drops before menstruation, insomnia follows. Here's the

Most people know that hormones affect mood during the premenstrual phase. Fewer realize they affect sleep in an equally measurable, mechanistically understood way. The luteal phase is literally sedating — and its end is literally a withdrawal. How Progesterone Promotes Sleep Progesterone doesn't act on the brain directly. Its metabolite allopregnanolone does. After progesterone is produced by the corpus luteum, enzymes in the brain and elsewhere convert a portion of it to allopregnanolone — a neurosteroid with potent effects on GABA A receptors. GABA A is the main inhibitory receptor in the central nervous system. It's the target of: Benzodiazepines (Valium, Xanax) Barbiturates Alcohol Allopregnanolone When allopregnanolone binds to GABA A receptors, it increases their sensitivity to GABA — amplifying the inhibitory signal. The result: reduced neuronal excitability, sedation, and anxiolysis. This is why the luteal phase, when progesterone (and therefore allopregnanolone) is high, is often characterized by deeper sleep and greater drowsiness — particularly in the first week after ovulation when progesterone is near its peak. The Pre Menstrual Withdrawal In the 3–5 days before menstr