Bleaching hair requires using a base which causes the hair to swell, a bleaching agent, and a “developer” to speed up the bleaching. But vital proteins of hair are oxidized along with the pigment you’re trying to remove. Use hair products containing protein to keep bleached hair supple and don’t re-bleach hair (just do touch-ups).
Avoid Excess Damage From Bleaching
Bleaching oxidizes more than just haircolor, treat lightened tresses with special care.