The foreskin, like all skin can be stretched extensively and their are many document cases of foreskins that have been stretched to two to three time the natural circumference.
Regardless of the reason for needing to stretch ones foreskin, the method is the same. That is, the foreskin requires gentle, even pressure distributed over a broad area of skin and repeated over many weeks (and months if the goal is significant cosmetic loosening).
For men with phimosis, a two week period of stretching the foreskin with the Novoglan gentle foreskin stretcher (balloon) will result in a 1 or 2 mm increase in circumference, which is usually enough for full, safe retraction. Some men need to stretch for many weeks to get a few millimetres of stretch around the circumference.
The most important aspect about stretching a tight foreskin, is that the use of hard and localised (pointed pressure) is counter productive and can in fact cause acute and long term injury. slow, gentle, even and regular pressure over time will generate a good level of foreskin stretching.
For more information about phimosis stretching, checkout our Novoglan Video or product page.