Brexanolone is a 3-hydroxy-5alpha-pregnan-20-one in which the hydroxy group at position 3 has alpha-configuration. It is a metabolite of the sex hormone progesterone and used for the treatment of postpartum depression in women. It has a role as a human metabolite, an antidepressant, a GABA modulator, an intravenous anaesthetic and a sedative.