Definition, Causes, and Treatment of Micropenis

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What Is a Micropenis?

Micropenis is a clinical term used to describe a very small penis. In an ideal world (where we didn’t assume that being too far from a norm is automatically cause for concern) being born with a very small penis would not be considered a medical problem unless the penis was causing pain, or not functioning the way a newborn penis should. However, because we do associate health at birth with a variety of norms, infants born with very small penises can be labeled as in need of medical attention (even if they aren't).


People born with micropenises that either received no treatment, or received treatment that had no effect, can go through puberty and move into adulthood and still have a micropenis. The generally accepted definition of a micropenis is a penis that is "more than 2.5 standard deviations" below the average penis length for the age of the individual. This is just a statistical term that means a certain length away from average, based on the average penis size in the population.

Even though researchers disagree on what constitutes average penis size a micropenis is considered in newborns to be around 3 /4 of an inch (1.9 centimeters) in length, and in adults to be less than 2.8 inches (7 centimeters)in length.

What Causes Micropenises?

Micropenises are the result of a difference in fetal development. Most often the cause of a micropenis is chromosomal and hormonal, and results from some problem in either the making of, or body’s response to, androgen.
Research on fetal development suggests that there are two stages of penile development in fetuses. The first happens early in fetal development is when androgen triggers the development of the penis and scrotum from its undifferentiated state. The second, which happens later on in fetal development, occurs when androgen influences the further growth of the penis.
It is thought that a micropenis is the result of the first stage happening but not the second (so the penis looks like most penises, but it is much smaller).

Because the term micropenis is really just a descriptive one, there could be many reasons someone is born with a micropenis. As many as a third of people born with a micropenis don’t fit into an easily identifiable category to explain the cause of it.

Many adult men who think they have a micropenis would not fit the clinical diagnosis. If you are concerned that you may have a micropenis the easiest first step would be to talk with your doctor.

Can You Have Sex With a Micropenis?

You can absolutely have sex with a micropenis. For adult men who have true micropenises this may be a huge concern. The first thing to point out is that if you want, you can have great sex without a penis at all. So regardless of size, sex is still out there.

In terms of the sexual functioning and response of the micropenis itself, reports vary. Certainly many men who have micropenises report having satisfying sexual intercourse as well. There haven’t been many studies, but one reported that 75% of men with micropenises reported satisfying sexual intercourse.

Yet another recent study which examined the nighttime erections of men with micropensises found them to be different from men without micropenises. Again, I would suggest that sexual satisfaction and functioning are not categories to be left to “researchers” alone, and how you feel about it is more important than what laboratory research can tell us.

Is There Treatment for a Micropenis?

Given the society we live in, where a man’s worth is measured by the size of everything from his car to his income to his penis, it’s not surprising that many men think a small penis is, by definition, a broken penis. But this isn’t the case. If you are an adult with a micropenis the “treatment” may be more about accepting that your body is okay, and can give you the same amount of pleasure as other bodies than any more significant intervention.

Most treatments for micropenises happen just after birth and around puberty.

This treatment usually involves hormones to stimulate further penile growth.

For adult men with true micropenises there are also surgical options, although these surgeries tend to have low satisfaction ratings, and a recent review suggested that surgery should not be recommend to patients specifically because of the lack of satisfaction.


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