Wash hair. If you have gotten your perm within the past couple days and want to undo it, immediately wash your hair. Use a deep cleansing shampoo and wash repeatedly. If your perm is more than a few days old, this method will not be effective.
Apply hair oil treatments. Oil treatments tend to weigh hair down and reduce curl. Your perm will be less apparent as the hair oil will lead to looser curls.
Condition hair with deep conditioning treatments. Like oils, deep conditioners discourage curliness. If you apply regularly, you will see a reduction in your perm curls.
Cut your hair. If your perm has grown out somewhat, you can simply cut off the remaining permed hair. This is the only completely effective method for removing a perm. Once your hair has been chemically altered, it cannot return to its natural state. New hair that has not been permed needs to grow in and replace the permed hair, in order for your hair to be truly perm-free.
Get a chemical hair-straightening treatment from a professional hair dresser. Hair straightening treatments work similarly to perms. The hair dresser will apply chemicals to your hair but instead of wrapping the hair in curlers or rods, she will simply comb the hair straight. She will then continue to comb your hair, using a fine-toothed comb, until the hair begins to relax and become free of curls.
Use a straightening iron to temporarily straighten your permed hair. Unlike chemical straightening which is permanent, straightening irons will simply straighten your hair until it gets wet. You will need to use a straightening iron after every washing.