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
Refractory period (sex) to a highly energetic post-orgasmic state. According to some studies, 18-year-old males have a refractory period of about 15 minutes, while those in their 70s take about 20 hours, with the average for all men being about half an hour. Although rarer, some males exhibit no refractory period or a refractory period lasting less than 10 seconds. A scientific study attempting to document natural, fully ejaculatory, multiple orgasms in an adult man was conducted at Rutgers University in 1995. During the study, six fully ejaculatory orgasms were experienced in 36 minutes, with no apparent refractory period. Later, P. Haake "et