Refractory period (sex) for treating sexual dysfunction. Sildenafil, used in the treatment of erectile dysfunction, was found in one scientific study to have caused "a decreased postejaculatory erectile refractory time (3.2 ± 0.7 vs. 6.4 ± 0.7 minutes)" in men diagnosed with premature ejaculation. It is additionally proposed that the gonadotropin inhibitory hormone (GnIH), which is considered to inhibit the hypothalamic-pituitary-gonadal axis and sexual functions causes refractoriness of the post-ejaculatory refractory period. This hypothesis also supports the increase of oxytocin and prolactin after orgasm in accordance with the previous studies. One alternative theory explains the male refractory period in terms of a peripheral
Effective refractory period Effective refractory period In electrocardiography, during a cardiac cycle, once an action potential is initiated, there is a period of time that a new action potential cannot be initiated. This is termed the effective refractory period (ERP) of the tissue. This period is approximately equal to the absolute refractory period (ARP), it occurs because the fast sodium channels remain closed until the cell fully repolarizes. During this period, depolarization on adjacent cardiac muscles does not produce a new depolarization in the current cell as it has to refract back to phase 4 of the action potential before a new action