Precursor to metabolite: Progesterone to Allopregnanolone

Progesterone is converted to Allopregnanolone by 5-alpha-reductase → 3-alpha-HSOR.

The pair

Progesterone — Natural progestogen for endometrial protection and luteal support; often sedating.
Allopregnanolone — Progesterone-derived neurosteroid and a potent positive modulator of GABA-A — the model for brexanolone.