Penis Size: What’s Normal, What’s Not
You might think that as long a man’s penis works, he would have no problem with it. You would be wrong.
Penis size is a key element of a man’s self-image. Yet when he’s not boasting to other men, the average man significantly underestimates the relative size of his penis.
Here’s an example: Over a two-year period, 67 men asked an Italian hospital for surgical correction of a small penis. All turned out to have normal-size penises.
“A few days ago, I had a patient who spent an hour taking measurements of his penis and thinking it is too small,” Gilbert says. “Yet it was normal.”
That man isn’t alone. About 45% of his brethren want a bigger penis. Never mind that 85% of heterosexual women say they are satisfied with their partners’ penis parameters.
How to Measure a Penis
Men may be surprised to learn that penis length isn’t measured on the erect penis. Too many variables are involved.
Instead, the most reliable penis measurement is called SPL — stretched penis length. The longer a man’s SPL, the longer his erect penis length, according to studies done on brave young men who volunteered to have erection-stimulating penis injections.
To learn your SPL, measure the penis while it’s flaccid. Press the ruler tight against the pubic bone at the base of the penis. Don’t just measure from where the penis separates from the scrotum, or you’ll lose precious centimeters. Now gently, but very firmly, stretch the penis as far as it will go. Measure from the pubic bone to the tip of the stretched penis.
Did you get five and a quarter inches? If so, you are exactly normal. Most adult men are within about a half inch of 5.24 inches, according to statistics Palmer has compiled. Nearly all studies of penis length come up with a similar measure.
If you’re a little smaller than that, you’ve got lots of company. Just as many men are below average penis size as above it.
How big is big? According to Palmer’s statistics, only 0.6% of men have an SPL of 6.8 inches or more. But too big isn’t what men tend to worry about.
MICROPENIS: WHEN A PENIS REALLY IS TOO SMALL
There is, of course, such a thing as a very small penis. The medical term “micropenis” applies to the 0.6% of men with the smallest penises. According to Palmer’s statistics, an SPL of three and two-thirds inches or less indicates a micropenis.
Even then, U.S. doctors hesitate to recommend surgery for a man whose SPL is longer than three inches. That’s because surgery is controversial and risky.
Micropenis isn’t usually something a man discovers when he’s an adult. It’s usually caused by genetic or hormonal abnormalities that cause other, more serious health problems early in life.
That’s because the penis starts to develop when a fetus is just 8 weeks old. By week 12, the penis has developed and begins to grow. During the second and third trimesters, male sex hormones cause the penis to grow to normal length. Factors that interfere with hormone production and hormone action stunt penis growth.
When discovered in infancy, micropenis can be treated with testosterone, which can stimulate penis growth in childhood, even after puberty. While the safety and long-term efficacy of this treatment remains to be proved, available data suggest the treatment does not affect normal development during puberty.
For adults with micropenis, the options are few.
“For true micropenis, there is not much you can do that is adequate for the adult patient, except for putting in a penile prosthesis,” Gilbert says.
Fortunately, micropenis is a rare condition. Far more common is what Palmer and colleagues call “the constellation of conditions that make the penis look diminutive and small” — inconspicuous penis.
Many men worry about the size of their erections. Many more worry about how their penis looks when it’s limp, studies find.
So how can a man know if he’s normal, super-sized, or small? Not by his shoe size, a common and disproved myth about estimating penis length. Like so much else in life, direct measurement is the key.
Can Devices Make a Small Penis Larger?
Traction devices that stretch the penis may actually add an inch or so to penis length, based on small studies and anecdotal reports. Gilbert says he is following two patients who are using these devices in an effort to make their penises longer.
“These devices have to be worn for several hours a day, for many months,” he says. “Most people, even if they are highly motivated, don’t have that kind of time. So I’m not sure a lot of patients have the time or energy or perseverance to do that.”
Vacuum devices may help men with erectile dysfunction achieve an erection — but they do not make the penis larger.
Can Regenerative Medicine Make a Small Penis Larger?
However, there is one area of research with intriguing possibilities: regenerative medicine. Scientists have been able to grow animal penises in the laboratory by seeding scaffolds with the animals’ own cells. These penises then were successfully transplanted.
Already a group of researchers in Beijing, China, have reported using a similar technique to treat 69 patients with what they called small penis syndrome. In this case, the tissues were grown from the patients’ own scrotal skin and grafted to their penises to increase their girth.
“With regenerative medicine, the sky is the limit,” Palmer says. “We might have this as an option down the line.”
“Regenerative medicine is still not ready for prime time,” Gilbert says. “These things have a lot of potential, but nothing we can offer to patients in the near future.”