It depends how much you've gained, and how long it took to make that gain. If, for example, you only gained half of an inch, over a period of several months, and you stopped Penis Enlargement cold turkey, you would lose all of your gains.
In order for gains to become permanent, you must cement them. This takes time. If you've been Penis Enlargement'ing for x years, then you should cement for x/2 years. While cementing, at times you will notice that you are actually losing a little bit of length, as you are decreasing the time and the intensity of your workouts over the months. This is normal.
If you lose length during the cementing process, simply bump up the intensity until you get back to the length that you want to cement. Because you are stressing your tissues every single day, they will not fully heal, and so even if there is some retraction, bumping up the intensity will bring you back to your desired length very quickly. You will not need to work much to get it back. But if you are slacking off, it will be slightly more difficult, and therefore more time consuming. Obviously.
The goal is to reach a point where the decrease of stress levels no longer causes a retraction. This can take many months, or even a year, depending on how much you've gained. The more you've gained, the longer the time it took you to make those gains, and so the longer it should take to cement those gains. Generally speaking. Only you can judge when it is time to stop (when the gains have become permanent). Everyone is different.
But, as mentioned above, if you want to be safe, you should cement for about half of the time that it took you to make all of your gains. So, for example, if you've done Penis Enlargement for two years, and gained, say, 1.5 inches, you would need to cement those gains for a maximum of one year before retiring. If, however, you are one of those guys who doesn't take Penis Enlargement seriously, Penis Enlargement'ing on and off for many years, then you should know where you stand as far as permanent gains are concerned. If you had gained one inch, and then stopped Penis Enlargement cold turkey for a full year, and lost half of an inch, then you would know for a fact that the other half inch is permanent.
That is pretty much all you need to know about cementing. I hope this helps you guys. Good luck.