Once you've gone through with lightening your hair, the most important thing you can do is be gentle with it considering it's been through a lot with all of the bleach and chemicals.
"Weekly hydration or Olaplex No. 3 Hair Perfecter ($28) treatments at home will be very important to replenish the moisture in the hair," Tang said. "Also, be careful with products that have any kind of pigment, such as a yellow hair serum or oil."
The aforementioned yellow products can give your hair a brassy look over time, which is why it's recommended that people with lighter hair colours use purple shampoo to correct the colour and cancel out the yellow. A few of our favourites are the Kérastase Blond Absolu Anti-Brass Purple Shampoo ($35), Not Your Mother's Blonde Moment Treatment Shampoo ($8), and Moroccanoil Blonde Perfecting Purple Shampoo ($24).