What do purple shampoos do?
“Purple shampoos cancel out unwanted yellow tones in the hair,” says Bodt. If you’re a faux-blonde looking for upkeep, purple shampoos are an essential investment. “For blondes who are looking for more neutral, cooler, or ashier tones, purple shampoos can help offset the warmer tones that appear in blonde hair over time,” adds Lynch.
Why does blonde hair become brassy?
“Blonde hair goes brassy because bleaching or lifting does not remove all of the underlying golden/copper/red pigments in the hair when hair is lightened,” says Lynch. “These underlying pigments that remain after lightening are yellow, orange, and red in tone. As the cool pigments fade, the warm underlying pigments left behind after coloring become a larger part of the overall hair color. This warmer toned color is often described as having a brassy appearance.”
Can only faux blondes benefit from purple shampoos?
“Color shampoos can even work on brunettes but if you want to cancel orange tones which typically happen on brunettes you might want to try a blue shampoo,” says Bodt.
How often should you use a purple shampoo?
“Depending on the hair porosity and desired tone, I’d say once a month,” says Bodt. “If you use too often the hair can get overtoned and muddy in appearance.” If you’re not seeing the results you’d like with this frequency, consulting a hairstylist or investing in a toner or gloss can help.