While the study of the penis and its sensory anatomy is comprehensive, the clitoris has remained relatively neglected by medical researchers. For decades, the bulb-shaped erogenous organ was presumed to have around 8,000 nerve endings, an oft-cited figure pulled from a study of cows mentioned in the 1976 book, "The Clitoris."
But according to a new study conducted by researchers at Oregon Health & Science University, previous estimates were off—way off. In the first-ever count of its kind, researchers discovered that the human clitoris contains 10,281 nerve fibers on average, which exceeds the outdated former figure by 20 percent.
The study was led by Blair Peters, M.D., an assistant professor of surgery at the OHSU School of Medicine and a plastic surgeon who specializes in gender-affirming care. For the study, Blair and his research team magnified clitoral nerve tissue from seven adult transmasculine volunteers who were undergoing gender-affirming surgery.
Matthew D. Wood, Ph.D., Associate Professor of Surgery at Washington University in St. Louis School of Medicine and part of Blair’s research team, explained the process of magnifying and quantifying nerve fibers in the clitoris: “For analysis and high-resolution imaging of the nerve, the [clitoral nerve tissue] is processed and stained using osmium tetroxide, which stains lipids a very dark ‘black’ color as visualized using a light microscope,” Wood said. These stained specimens were imaged and assessed to allow researchers to measure the total number of nerve fibers.
Using this staining and imaging process, researchers counted an average of 5,140 dorsal clitoral nerve fibers in each individual clitoral dorsal nerve, the main nerve responsible for clitoral sensation. The dorsal nerve is symmetrical, so the research team doubled this number to get an average of 10,280 nerve fibers. As Peters noted in an OHSU news release, the clitoris also has other, smaller nerves beyond the dorsal nerve, so the total number of nerve fibers is likely even greater.
"It's startling to think about more than 10,000 nerve fibers being concentrated in something as small as the clitoris," Peters said in the release.
For context, Peters cited the number of nerves of a larger part of the human body, the hand.
"The median nerve, which runs through the wrist and hand and is involved in carpal tunnel syndrome, is known for having high nerve fiber density," Peters said. "Even though the hand is many, many times larger than the clitoris, the median nerve only contains about 18,000 nerve fibers, or fewer than two times the nerve fibers that are packed into the much smaller clitoris."
A quick overview
The clitoris may be smaller than a hand, but it's much larger than the visible pea-size "hill" above the urethra that many people consider to be the entire clitoris. That tiny, hooded nub—technically called the glans clitoris—is "only the tip of the iceberg," as the common refrain in clitoral anatomy goes. The visible glans clitoris accounts for less than a fifth of the full organ, which extends beneath the surface to include teardrop-shaped bulbs, two arms and a shaft. From the tip of the glans to the end of one arm, the clitoris can measure around 4 inches long.
As we now know, the clitoris has 10,000-plus nerve endings, which is significantly higher than the number found inside the vagina. That's why most women—73 percent, to be specific—can't orgasm from penetration alone but instead require stimulation of the clitoris to reach climax.
With their findings, Peters and his colleagues hope to improve sexual sensation for phalloplasty patients and develop new surgical procedures to repair damaged nerves. One use of phalloplasty surgery is to create a new penis for transmasculine patients.
"Better understanding of the clitoris can help everyone, regardless of their gender identity," Peters said in the release. "But it's important to acknowledge this research is only possible because of gender-affirming surgeries and transgender patients. There's something profound about the fact that gender-affirming care becoming more commonplace also benefits other areas of healthcare. A rising tide lifts all boats. Oppressing or limiting transgender healthcare will harm everyone."
Peters presented the results in October 2022 at a conference in Miami hosted by the Sexual Medicine Society of North America and the International Society for Sexual Medicine. Findings are considered preliminary until published in a peer-reviewed journal; a paper detailing the findings is set to be published in the Journal of Sexual Medicine.