No study, no scientific board, not a single medical board has said male circumcision affects sexual functioning.
You might wish you hadn't said that - mainly because it's so silly and self-refuting. Would you even expect there to be "studies" proving finger amputation affects hand functioning? I certainly don't want my tax dollars funding such studies.
Circumcision removes about 15 square inches of sexual interface. It leaves the glans and mucosa to dry and callous, as put forth by the pro-circ African controlled trials on HIV. It eliminates the frictionless rolling/gliding mode of stimulation for a man and his partner afforded by the slinking of the slack skin. It changes the girth of the penis. The diameter increases by 4 skin thicknesses while the skin is rolled over the glans. Circumcision damages the highly sensitive frenulum and removes more than half of the sensual pleasure-receptive nerve endings a male is born with, which are concentrated near the tip of the foreskin (as identified by Taylor
Erogenous Tissue Loss after Circumcision).
Done in infancy circumcision often leads to hairy shaft, tight painful erection, smelly ugly skin bridges, pitted glans, painful jagged bulgy truncated vein, mal-opposition, stitch tunnels, skin tags, meatal stenosis, etc (and of course hundreds of deaths every year, which put a real damper on sexual function). You really do need to look over the circumcision damage pages:
How to Identify Circumcision Damage in the Adult Male
But you wanted studies.
This one's from a pro-circ guy (an infant circ device is named after him) in 1959.
The Erogenous Zones: Their Nerve Supply and Significance It says primary erogenous zones are "found in the mucocutaneous regions of the body." That is to say where the foreskin rolls over at the tip and the skin transitions from hair-bearing skin (cutica) to mucosal skin, that's a "mucocutaneous" region. The end of the foreskin is primary erogenous zone. Amputate an erogenous zone, change sexual function.
This one measured the force required to penetrate an orifice, for cut vs intact.
The intromission function of the foreskin. It was a 10-fold improvement, from 5N down to 0.5N of force with an intact foreskin (measured for men with foreskin that could cover the glans while erect).
Here, John Money of the famous John/Joan case writes in the Journal of Sex Research about some men cut as adults, all of whom reported changes in sexual function:
Adult Penile Circumcision: Erotosexual and Cosmetic Sequelae
Here's a paper from the British Journal of Sexual Medicine describing the exquisite rolling/gliding action of the foreskin, so you know I didn't just make it up:
The Case Against Circumcision
These two show that even when adults are cut to relieve severe problems, around 40% will report "dissatisfaction" with the outcome, while many more have measurable diminutions, like erectile dysfunction, loss of sensitivity, and also premature ejaculation:
Adult Circumcision Outcomes Study: Effect on Erectile Function, Penile Sensitivity, Sexual Activity and Satisfaction.
Penile Sensitivity and Sexual Satisfaction after Circumcision: Are We Informing Men Correctly?
This one published in New Zealand Medical Journal describes the association between female arousal disorders and vaginal dryness with circumcised partners:
Effects of male circumcision on female arousal
And of course when about 200 men had 17 spots on the penis carefully measured, the 5 most sensitive spots were on the foreskin:
Wiley InterScience :: Session Cookies
I think these are all irrelevant. Every person has a basic human right
to a whole intact body. Even if something was utterly benign - like say
there was a safe pill you could give a baby that would mean he would
never have facial hair to shave - it would be unethical to make an
irreversible cosmetic choice on behalf of a non-consenting person.
-Ron
. Do you?
