It depends on the doctor. Theirs site called phalloboards that discuss this. I had 2 rounds of pmma from Avanti derma clinic and was extremely happy. I might consider doing one last round but with Dr.Rupeka in Ohio since he does the underside .
its permanent , so I recommend you do HA first just to see how you like it, then determine if wanting to do permanent .
i wish their is effective way to increase length since that’s what I prefer righ now