Golexanolone, also known by the developmental code name GR-3027, is a neurosteroid medication which is under development for the treatment of hypersomnia and hepatic encephalopathy. It acts as a negative allosteric modulator of the GABA<sub>A</sub> receptor. The medication selectively antagonizes the stimulatory actions of inhibitory neurosteroids like allopregnanolone and tetrahydrodeoxycorticosterone (THDOC) at the GABA<sub>A</sub> receptor, while not affecting the activation of the GABA<sub>A</sub> receptor by ó-aminobutyric acid (GABA).