Famous How Long After Perm Can You Wash Hair References. One of the most common myths is that you have to wait 48 hours after a perm before using shampoo. A perm always has to grow out—but, thankfully, they typically grow out.
Web when can i wash my hair after a perm? Web to wash your hair after a perm you have to wait 48 hours. Web after you get a perm, how long it lasts depends mainly on how long your hair is.