Most hair stylists recommend waiting at least 48 hours before showering after a perm. Check with your stylist for specific instructions in case she recommends letting your perm set longer. Depending on the chemicals and techniques used, your stylist may suggest a longer amount of time.
Wetting your hair earlier than the recommended time may negatively impact your perm. Allow the perm set for two to three days before shampooing your hair. Shampoos may also negatively interact with the chemicals used to set your perm, so use shampoos made for curly hair or perms specifically to help a perm last longer.