Although several functions of the foreskin are permanently destroyed by circumcision, others can be restored with non-surgical stretching techniques.
With gentle tension over long periods of time, the remaining shaft skin can be expanded to simulate a foreskin. This protects the head of the penis from abrasive clothing and extreme temperatures, and also restores the mechanical functions of the foreskin, which glides to and fro during sexual activity.
Many men have success with no-frills manual tugging, and there are also a variety of affordable restoration devices on the market, which can be worn under your clothing throughout the day. Foreskin restoration should not cause any damage. If it hurts, you’re doing something wrong.
For more information, see the Beginner’s Guide to Foreskin Restoration.