An antiprogestin, CDB4124, blocks progesterone's attenuation of the negative effects of a mild stress on sexual behavior

► Ovariectomized rats show lordosis behavior following 10 μg estradiol benzoate. ► Sexual behavior is reduced after 5 min of restraint. ► Progesterone attenuates the negative effects of the restraint. ► The progesterone receptor antagonist, CDB4124, blocks progesterone's effect.