The foreskin is fused to the head of the penis in infancy, providing protection. The preputial sphincter at the tip specifically serves as a simple barrier that keeps out environmental contamination. It is not designed to be pulled back in infancy or childhood. Meatal stenosis (narrowing or closing of the urethral hole) occurs in approximately 10% of circumcised boys and sometimes requires painful corrective surgery.
When the mucosa of the glans are exposed to chafing, the glans protects itself by keratinizing (similar to a callous). Foreskin keeps the glans internal, as it is supposed to be. The more the glans keratinizes, the less it can feel.
With natural lubricant, men with foreskin generally do not need lotion or lubricant for sexual activity. Women benefit from the lower risk of friction and dryness that a man's foreskin provides. It also serves to seal in the female sexual partner’s lubrication, preventing it from losing its effectiveness.
The foreskin is densely innervated with multiple types of nerves. These nerves respond to stretch, fine touch detail, temperature, and more. Foreskin feels really good.
The presence of the male foreskin is inherently pleasurable in intercourse. In particular, it stimulates the female clitoris in certain sexual positions.
The mechanics of sexual activity are changed dramatically with circumcision, from rolling to rubbing. Circumcised males "tend to thrust harder and deeper, using elongated strokes," but intact males tend "to thrust more gently, to have shorter strokes, and tended to be in contact with the mons pubis and clitoris more." Also, the sliding/gliding motion of the foreskin over the glans and corona is deeply pleasurable for the male and makes initial insertion of the penis easier and more comfortable for both partners.
Like the eyeball, inside of the cheek, and vagina, the glans is designed to be a protected internal organ.
The structures of the foreskin provide full, natural levels of neurological feedback, which allow robust control over erection, arousal, and orgasm.
The foreskin contains the most pleasurable parts of the penis. This complete sensation, elimination of friction and pain, and other functions reduce the risk of erectile and ejaculatory problems.
The foreskin protects the glans from being aroused at inappropriate times, reducing involuntary erections. Feedback helps prevent premature ejaculation.
It's common sense: if you cut part of something off, you make it smaller. This has been observed by professional journals, including one which found that the penises of circumcised males were an average of almost 1 centimeter shorter.
The specialized nerves don't just feel good - they feel well.
Apocrine glands in the foreskin may release pheromones, signal chemicals that help encourage sexual arousal in the man's partner. The foreskin also prevents discoloration of the red/purple/pink head of the penis, preserving the sexual signal conveyed by this natural coloration.
Specialized cells provide defense against unhealthy microbes. As long as the man washes occasionally with water, not soap, the microbial balance of the area remains healthy and infections are prevented.
An intact man is safe from "not enough skin" erection problems. The foreskin is a part of a whole penile skin system – it expands and moves along with erection. In addition, the frenar band massages the glans during sliding/gliding, regulating blood flow and preventing the erection from becoming "too hard," which can happen with some men.
Without correct protection and mechanical function, some men experience a burning or other pain after ejaculation.
The foreskin has various other sexual, cosmetic, neurological, and other functions. For example, it provides protection from cold, burns, and trauma, and it contains a rich network of blood vessels to support good penile function.
The foreskin is supposed to be there, for many reasons.
1. See more on this at "The development of retractile foreskin in the child and adolescent" from Doctors Opposing Circumcision. The foreskin should never be retracted in this state. The American Academy of Pediatrics says:
"Most boys will be able to retract their foreskins by the time they are 5 [others sources say the average is 10.5] years old, yet others will not be able to until the teen years. As a boy becomes more aware of his body, he will most likely discover how to retract his own foreskin. But foreskin retraction should never be forced. Until the foreskin fully separates, do not try to pull it back. Forcing the foreskin to retract before it is ready can cause severe pain, bleeding, and tears in the skin."
Premature retraction is the cause of nearly all "foreskin problem" stories in the United States. The foreskin is fused in infants and children as a protective structure and is not designed to be pulled back until later in life.
2. Meatal stenosis is a condition where the urethra (hole) narrows or begins to close up. Medical articles on incidence of meatal stenosis:
3. Cold CJ, Taylor JR. The prepuce. BJU Int. 1999;83(Suppl 1):34-44.
4. Sorrells ML, Snyder JL, Reiss MD, Eden C, Milos MF, Wilcox N, et al. Fine-touch pressure thresholds in the adult penis. BJU Int. 2007;99:864-9.
5. See Money J, Davison J. Adult penile circumcision: erotosexual and cosmetic sequelae. J Sex Res. 1983;19:289-92. See also Bensley GA, Boyle GJ. Physical, sexual, and psychological effects of male infant circumcision: an exploratory survey. In: Denniston GC, Hodges FM, Milos MF, eds. Understanding circumcision: a multi-disciplinary approach to a multidimensional problem. New York: Kluwer Academic/Plenum Publishers; 2001. p. 207-39.
6. O'Hara K, O'Hara J. The effect of male circumcision on the sexual enjoyment of the female partner. BJU Int. 1999;83(Suppl 1):79-84. Significant discussion of the various sources, with references, is available in this summary article.
7. See especially Sorrells ML, Snyder JL, Reiss MD, Eden C, Milos MF, Wilcox N, et al. Fine-touch pressure thresholds in the adult penis. BJU Int. 2007;99:864-9.
This point is worth extended discussion, as a recent study by Bossio et al. has been frequently misinterpreted recently. Here are a few points from the article here by Doctors Opposing Circumcision:
8. Again, the following articles are summarized, explained, and discussed here.
See also surveys with statistically significant groups of males reporting difficulty with erection and ejaculation after adult circumcision:
9. Richters J, Gerofi J, Donovan B. Are condoms the right size(s)? A method for self-measurement of the erect penis. Venereology. 1995;8(2):77-81.
10. This is still a tentative point, as much of the body is simply not yet understood. Further study of apocrine glands is required. See Fleiss P, Hodges F, Van Howe RS. Immunological functions of the human prepuce. Sex Transm Infect. 1998;74:364-7. Also, see the details presented in this important journal article on the structure and anatomy of the foreskin.
11. Insufficient remaining skin to accommodate erections is a very common complaint from circumcised children and adults. It has also been mentioned in academic literature – see, for example, here.
12. Publication of research on this point is still pending, but Ken McGrath, Senior Lecturer in Pathology at the Faculty of Health, Auckland University of Technology and Member of the New Zealand Institute of Medical Laboratory Scientists, explains the details here at the 12:15 mark.
Version 1.4. Updated July 2017.