No, just the new growth and the transition between Straightened and new growth is treated. The other hair is protected by using oil or conditioner so the solution will not saturate into the previously straightened hair. If there is still curl or wave in the previously treated hair or more than 4 month after previous hair straightening, special solution will be applied, but for a shorter period of time.
Crystallizing special solution is designed for treated hair, and this will give more protein to your hair to refresh previous hair straightening. Also we will iron the whole hair again, or otherwise the transition between will have unwanted line. Note: the retouch is often more difficult to perform, so it is strongly recommended that you go back to the same stylist as before or find someone better if you were not happy with your first straightening!