How I Determine Implant Size: The Craft Behind Penile Enhancement

One of the most common and important questions I get from patients considering penile enhancement with a subcutaneous implant (that is the Himplant/Penuma) is this:

“How do you determine the size of the implant?”

Primary Factors:

The Himplant comes in three sizes (L, XL and XXL) and two lengths (standard and extra-long).

When we speak of “size” we are really referring to the thickness and circumference of the implant. Size selection is driven by a few key factors:

• Pre-operative flaccid penile circumference measured at the mid-shaft
• Anatomical limitations (especially the size and trajectory of the urethra as it nears the head of the penis)
• Skin elasticity
• Desired aesthetic outcome (head-to-shaft proportion)

The decision between a standard and extra-long implant is determined by a patient’s pre-operative stretched flaccid length and, to a lesser extent, the length of the glans from tip to coronal margin.

Dr. De Fazio’s Method:

While I can often assess size accurately from clinical photos, every patient undergoes an in-depth in-person evaluation to best predict the appropriate implant size. I start each evaluation with a measurement of the flaccid penile circumference at mid-shaft and the stretched penile length from tip to the pubic bone. As a rule of thumb, a circumference < 3.5 inches requires the large implant, a circumference between 3.5-4.5 inches will accommodate the XL implant and a circumference >4.5 inches may accommodate the XXL implant.

In terms of length, the standard length implant is appropriate for most men who are 7 inches or less in the flaccid stretched state. The extra-long implant is typically required only in the case of a flaccid stretched penis > 7 inches.

When a patient falls between two implant sizes, we have a discussion— Do you want more subtlety or more impact? How will your partner feel about a size increase? What balances best with your glans?

For men with a smaller glans, a smaller implant often yields a more natural, proportional look. A larger implant, in this case, can make the shaft appear visually disconnected from the head.