What is the common duration for a perm to set?

The common duration for a perm to set is typically between 1 to 2 hours. This time frame allows the chemical solutions used in the perm process to effectively alter the structure of the hair. During this setting period, the hair is kept in the desired curl formation through the use of perm rods and securely held in place with clips or bands.

The chemical process involves breaking and reforming the disulfide bonds in the hair shaft, which takes a sufficient amount of time to ensure the new curl shape is established and lasting. Factors like hair type, texture, and the specific perm solution used can influence the exact time required.

Shorter durations, such as 30 minutes or 5 to 10 minutes, are generally insufficient for the chemical changes to take effect, while an overnight application is impractical for most perm procedures due to the need for controlled conditions and to avoid potential damage to the hair.