Circumcised men do not have decreased penile sensitivity compared with other men, scientists say. Even when they had the operation when they were just babies, they show comparable responses to a variety of stimuli as men who have not gone through circumcision.

Previous studies have pointed out that circumcision reduces the risk of sexually transmitted diseases. Though the ultimate choice of doing it is left to parents, The American Academy of Pediatrics says circumcision for newborn males in the US may bring health benefits. The problem is that up to now, little research has been dedicated to the long-term effects of this operation, especially concerning the penile sensitivity of circumcised men.

It had been suggested that these men experienced decreased penile sensitivity. The latest study, published in The Journal of Urology, investigated this hypothesis by stimulating different parts of the penis.

First, the scientists examined whether the exposed glans penis of circumcised men was less sensitive than that of other men, and then, if the innervated foreskin was more sensitive than other sites of the penis.

Tactile detection, pain, warmth...

In total, 62 men, aged between 18 and 37 years old were recruited. Thirty had been circumcised as babies, the others were uncircumcised. They took part in a series of experiments, during which the scientists tested touch and pain thresholds at the forearm − a control site − and three to four penile sites − glans penis, midline shaft, proximal to midline shaft and foreskin, if present.

"We directly tested whether circumcision is associated with a reduction in penile sensitivity by testing tactile detection, pain, warmth detection and heat pain thresholds at multiple sites on the penis between groups of healthy circumcised and intact men," explains lead author Jennifer Bossio. She and her team observed little difference between the men, which suggests neonatal circumcision is not associated with changes in penile sensitivity.

The scientists also found that the foreskin of uncircumcised men was more sensitive to tactile stimulation than any other penile sites. However, this was not the case for other types of stimulus for which foreskin sensitivity was comparable to other sites tested.

Contrary to popular belief, this suggests that the foreskin is not necessarily more sensitive than other parts of the penis. Removing it during circumcision thus only has minimal long-term implications in terms of penile sensitivity, the scientists point out.

Normal sexual functioning

The study also looks at sexual functioning, using the International Index of Erectile Functioning (IIEF). This is a 15-item questionnaire measuring intercourse satisfaction, orgasmic function, sexual desire and overall satisfaction, over four weeks.

As no differences between participants were observed for any of these criteria, the study concludes that sexual functioning does not vary depending on circumcision status.

"Methodology and results from this study build on previous research and imply that if sexual functioning is related to circumcision status, this relationship is not likely the result of decreased penile sensitivity stemming from neonatal circumcision," concludes Bossio.