How Many Inches Can an Inflatable Penile Prosthesis Add?

Inflatable penile prosthesis (IPP) surgery is designed to restore erectile function in men with severe erectile dysfunction, not to increase penile length. According to the 2025 EAU Guidelines, penile prosthesis implantation should not be recommended solely for patients seeking penile lengthening.

In clinical studies, many men report a perceived shortening of the penis following IPP surgery. A prospective study found a slight reduction in erect penile length ranging from approximately 0.74 cm to 0.83 cm (about 0.3 inches) when comparing the results of intracavernosal injection versus inflated IPP. However, this change was not always statistically significant.

About 72% of men subjectively report a decrease in penile length post-surgery, even though objective measurements may not show significant change. The psychological impact of these perceived changes is a common source of postoperative dissatisfaction.

For men with severe penile shortening due to Peyronie’s Disease (PD) or trauma, more complex reconstructive procedures like the “sliding” technique or its modified versions (MoST, MuST) can be performed alongside IPP. These methods have shown mean length increases of approximately 3.1–3.2 cm (1.2–1.3 inches), but they come with high risk, including potential glans necrosis, and are not standard options for routine cases.

Some anecdotal sources suggest that up to 75% of men report increases in either length or girth after prosthesis placement, but these are often subjective, unmeasured, and not reliably supported by rigorous scientific evidence.

Patients considering IPP should have realistic expectations: the goal is to restore rigidity, not to enlarge the penis. Any expectations regarding size changes should be discussed thoroughly with a urologist, particularly if additional reconstructive procedures are being considered.