Allopregnanolone is a steroid hormone that serves as a potent positive allosteric modulator of the GABA receptor. It is also known as 5α-pregnan-3α-ol-20-one and 3α-hydroxy-5α-pregnan-20-one. Other synonyms for allopregnanolone include THP (tetrahydroprogesterone), pregnanolone, 3α,5α-Tetrahydroprogesterone, and 3α-hydroxy-5α-pregnane-20-one. Allopregnanolone has been shown to have a number of therapeutic benefits, including anxiolytic, sedative, anticonvulsant, and analgesic effects. It has also been implicated in the treatment of a range of psychiatric and neurological disorders, including postpartum depression, anxiety, and epilepsy.