Most Helpful Girl
I've had my hair professionally dyed, box-dyed it myself, had it bleached for color, bleached it myself for color and my hair has stayed pretty healthy.
Drink lots of water, use a heat protectant (CHI 44 Iron Guard or Redken AntiSnap serum) if you're going to use a flatiron or curling iron or blowdryer. And use hydrating shampoos and conditioners (Pantene and Herbal Essences are affordable and good quality). Also, use a deep-conditioning mask 1-2x a week, Ulta sells some good ones- link Make sure you get regular trims too so your dead/fried tips are gone and healthy hair can grow. Also, avoid using headbands and hairties with the metal clasps.