Oral progesterone decreases saccadic eye velocity and increases sedation in women

SummaryThe aim of this study was to investigate the neurophysiological and behavioural effects of a single dose of progesterone in women. Allopregnanolone is a metabolite of progesterone and a potent positive modulator of the GABAA receptor and produces sedative and anxiolytic effects. This study was designed to examine the effect of oral progesterone and the metabolite allopregnanolone in women. Women (n=15n=15) in their follicular phase received oral progesterone (400 mg) or placebo. Dependent measures included plasma levels of progesterone and allopregnanolone, saccadic eye velocity (SEV), subjective ratings (visual analogue scales), and reaction time. Administration of progesterone decreased SEV and increased sedation. This effect is probably due to enhanced GABA activity.