In sexuality, the refractory period is the recovery phase after (normally male) orgasm during which it is physiologically impossible for an individual to have additional orgasms. Most men are unable to maintain or achieve an erection during this time, and many perceive a psychological feeling of ‘satiation’ and are temporarily uninterested in further sexual activity. The penis may be hypersensitive and further sexual stimulation may even feel painful during this time frame.
The refractory period varies widely among individuals and across species, ranging from minutes to days. An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the refractory period and the amount by which oxytocin is increased may affect the length of each refractory period. Another chemical which is considered to be responsible for this effect is prolactin, which represses dopamine, which is responsible for sexual arousal.
Unlike most men, most women do not experience a refractory period immediately after orgasm and in many cases are capable of attaining additional, multiple orgasms through further stimulation. The female sexual response is more varied than that of men, and there are many women who experience clitoral hypersensitivity after orgasm, which effectively creates a refractory period. These women may be capable of further orgasms, but the pain involved makes the prospect undesirable.
By contrast, 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 a half-hour. Although rarer, some males exhibit no refractory period or a refractory period lasting less than 10 seconds. This, however, is not a lack of a refractory period per se (the ability to achieve another orgasm), but rather the ability to maintain an erection and resume sex immediately, whether to orgasm or not. Some studies have shown that Viagra is capable of cutting a refractory period in half.