Indeed, bleach is considered to be the most damaging methods of coloring. So only a professional hair stylist can do it. Why is bleaching so much dangerous? The problem is that repeated bleaching (agree, if you did it once, you are likely to do it again) can irretrievably raise the cuticle scales which allows a rapid and permanent loss of moisture.
Thus, bleached hair is likely to be dry, brittle, and fragile with split ends. It also has more pores which makes it more vulnerable to such chemical and non-chemical processes like straightening, curling, regular styling with blow-dryers etc. Thus, it can be concluded that since all bleaches have a damaging effect on the structure of your hair, the more often you highlight or bleach it, the more damaged your hair will be.
We recommend using only professional high-quality bleach powder to save your hair healthy.