Refractory period (sex)
In sexuality, the refractory period usually describes the recovery phase after orgasm during which it is physiologically impossible for a man to have additional orgasms. Though generally reported that women do not experience a refractory period and thus can experience an additional orgasm, or multiple orgasms, soon after the first, some sources state that both men and women experience a refractory period because women may also experience a period after orgasm in which further sexual stimulation does not produce excitement.
Factors and theories 
While the refractory period varies widely among individuals, ranging from minutes to days, most men cannot 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.
An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the male 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 the male refractory period is prolactin, which represses dopamine, which is responsible for sexual arousal. Because of this, there is currently an experimental interest in drugs which inhibit prolactin, such as cabergoline (also known as Cabeser, or Dostinex). Anecdotal reports on cabergoline suggest it may be able to eliminate the refractory period altogether, allowing men to experience multiple ejaculatory orgasms in rapid succession. At least one scientific study supports these claims, although cabergoline is a hormone-altering drug and has many potential side effects. It has not been approved for treating sexual dysfunction.
One alternative theory explains the male refractory period in terms of a peripheral autonomic feedback mechanism, rather than through central chemicals like oxytocin, serotonin, and prolactin. Autonomic feedback is already known to regulate other physiologic systems, such as breathing, blood pressure, and gut motility. This theory suggests that after male ejaculation, decreased wall tension in structures such as the seminal vesicles leads to a change in the fine autonomic signals sent from these organs, effectively creating a negative feedback loop. Such a mechanism is similar to decreased gastric and bowel motility once gastric contents have passed through. Once the feedback loop has been created, the refractory period remains until the loop is broken through restoration of the wall tension in the seminal vesicles. Once boys enter puberty and are capable of ejaculation, the refractory period is enacted. As men age, the time to restore tension in the seminal vesicles increases.
The female sexual response is more varied than that of men, and women are capable of attaining additional, multiple orgasms through further sexual stimulation. However, 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 in getting there makes the prospect undesirable.
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 a half-hour. Although rarer, some males exhibit no refractory period or a refractory period lasting less than 10 seconds. A scientific study to successfully 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 al. observed a single male individual producing multiple orgasms without elevated prolactin response.
Books and other reports 
A number of books assert that men are capable of eliminating the refractory period and having multiple orgasms similar to female multiple orgasms by learning to separate ejaculation from orgasm, and describe techniques they claim will help men stop ejaculation and thus eliminate the refractory period. In addition, many men who began masturbation or other sexual activity prior to puberty report the ability of having been able to achieve multiple, non-ejaculatory orgasms without refractory periods during that time in their lives. Most multi-orgasmic men (and their partners) report that multiple orgasms lead to a highly energetic post-orgasmic state.
See also 
- Rosenthal, Martha (2012). Human Sexuality: From Cells to Society. Cengage Learning. pp. 134–135. ISBN 9780618755714. Retrieved September 17, 2012.
- "The Sexual Response Cycle". University of California, Santa Barbara. Archived from the original on 25 July 2011. Retrieved 6 August 2012.
- Daniel L. Schacter, Daniel T. Gilbert, Daniel M. Wegner (2010). Psychology. Macmillan. p. 336. ISBN 1429237198,. Retrieved November 10, 2012.
- Irving B. Weiner, W. Edward Craighead (2010). The Corsini Encyclopedia of Psychology, Volume 2. John Wiley & Sons. p. 761. ISBN 0470170263,. Retrieved November 10, 2012.
- Panksepp, Jaak (2004). Textbook of biological psychiatry. Wiley-IEEE. p. 129.
- Haake, P.; Exton, M.S.; Haverkamp, J.; Krämer, M.; Leygraf, N.; Hartmann, U.; Schedlowski, M.; Krueger, T.H.C. (April 2002), "Absence of orgasm-induced prolactin secretion in a healthy multi-orgasmic male subject", International Journal of Impotence Research 14 (2): 133–135, doi:10.1038/sj/ijir/3900823, retrieved 2007-07-30
- Krüger TH, Haake P, Haverkamp J, et al. (December 2003). "Effects of acute prolactin manipulation on sexual drive and function in males". The Journal of Endocrinology 179 (3): 357–65. doi:10.1677/joe.0.1790357. PMID 14656205.
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- Whipple, B.; B. Myers and B. Komisaruk (1998). "Male Multiple Ejaculatory Orgasms: A Case Study". Journal of Sex Education and Therapy 23 (2): 157–62.
- Copeland, Pala and Link, AI: Voluntary Ejaculation and Male Multiple Orgasms (2004)
- Gedde, Margaret (MD PhD): The New Male Orgasm - Multiple orgasms without climax training guide
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- Havelock Ellis Studies in the Psychology of Sex, vol. vi, p. 552, F. A. Davis Co., 1910, Kindle Edition 2008 ISBN B0016PEMOS
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