Permanent hair smoothing West hair service for damage hair called kerasmooth which are made of hair smoothing and hair keratin treatment. This service is those hairs that are colored hair or their condition is very delicate.if hair smoothing was done on damage hair then it can be cause even more damage. Because damage hair requires treatment and not chemical How long will it last ? All this applies to how well you keep your hair. What products do you use on this? Checking hair every month is getting hairspa done from time to time. If you are doing all this from time to time, then it will remain forever. The hair that we straighten with a chemical process is never curly again in the future. Only new hair will grow, it will grow exactly as your natural texture