Should I Wash My Hair Before Dyeing It? The Do's and Don'ts, According to Two Hairstylists

Whether you're doing it at home or going to the salon

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Published Sep 6, 2024

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Should you wash your hair right before your color appointment? You may have heard conflicting things over the years. Some stylists say they’d never dye unwashed hair because it can prevent the color from taking, while others recommend leaving some oil on your scalp to ease any dryness or discomfort that can be caused by the dye.

After talking to two professional hairstylists at length, it turns out that both things can be true. It just boils down to what type of color you're after. Not to worry, we'll walk you through the nitty gritty details ahead.

Meet the Hairstylists:

Angela Hazelton is a colorist at Marie Robinson Salon in New York City. As one of New York's most sought-after colorists, her long-standing list of celebrity clientele includes Mariska Hargitay, Jessica Chastain, Amy Schumer, and Jennifer Connelly.
Wendy Burns is the national stylist for Henkel on their commercial brands Schwarzkopf and got2b. She is currently based in South Carolina but travels internationally and throughout the United States for events, photoshoots and education for Henkel's color and styling products. Wendy has 33 years experience styling hair and her work has been featured in many social media and ad campaigns.

Should I Wash My Hair Before Dyeing It 1: an older woman coloring her hair at home

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Should You Wash Your Hair Before Dyeing It at Home?

"I suggest using a clarifying shampoo on your hair the night before an at-home color to remove any possible build up of products or minerals from hard water," says Burns.

Another pro tip: Prep your hair with a treatment before you dye it. "Imagine your hair is a road full of potholes. Those potholes in the road can prevent hair color from looking even. Sometimes the hair can grab too much color and it looks too dark or not hold it at all in those areas," explains Burns. She likes Schwarzkopf Keratin colors for at-home color, noting that they all come with "a pre-treatment serum that you apply before dyeing to fill in those potholes and create a smooth surface, so the color glides on evenly from root to tip."

Should I Wash My Hair Before Dyeing It 2: a woman getting her hair shampooed at a salon

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Should You Wash Your Hair Before Getting a Single-Process Color (aka All-Over Color)?

Avoid washing your hair *right* before your appointment. “Single-process color is applied directly to the head and scalp,” Hazleton tells us. “If you wash your hair the morning of your color appointment, you remove all the excess oils, which act as a protective barrier and helps reduce any scalp irritation or itchiness during your treatment," she explains. And if you're a frequent shampooer, hold off for at least 12 to 24 hours before your appointment so your hair is clean, but you still have a little oil on your scalp to shield it from irritation and staining.

Should I Wash My Hair Before Dyeing It 3: a close up image of hair being bleached

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Should You Wash Your Hair Before Getting a Double-Process Color (aka a Bleach and Tone)?

Come in with unwashed hair. As Hazelton explains, “It is essential to have dirty hair (aka a day or two since your last wash or enough that it feels a little oily), or else the bleaching process can be unbearably uncomfortable for many people.” Again, the natural oils act as a barrier between the bleach that’s required to lighten your hair and your scalp.

If you're ever unsure of how to prep for your appointment, Burns recommends asking your stylist directly. "Many stylists offer a pre-treatment that's meant to remove the excess minerals found in water from the hair. These minerals can react with the chemical components of hair color and produce a brassy result. Consulting with your stylist—especially if you're a new client—is always a great idea, so they can evaluate your hair and you can know what to expect at your appointment."

Should I Wash My Hair Before Dyeing It 4

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Should You Wash Your Hair Before Getting Highlights or Balayage?

Come in with clean hair. “Unlike single- or double-process color, highlights aren’t applied directly to the scalp, so it’s OK to wash your hair the morning of your color appointment,” says Hazelton, adding that she actually prefers that her highlight clients come in with clean, detangled hair rather than hair that hasn’t been washed in multiple days. “It gives your colorist a better sense of how the color grew out and how much it’s oxidized. Greasy hair always appears much darker than it actually is, and if there is loads of dry shampoo or build-up in the hair, it can it harder to comb through when highlighting,” she explains.

Are There Any Exceptions for Washing Your Hair Before Dyeing It?

Regardless of which color service you’re having done, if you’re someone who uses root concealers to hide grays in between appointments, you should make sure you give your hair a thorough shampoo before going to the salon.

“Some root concealers coat the hair so much and have a waxy or even tacky texture that’s hard to remove with just one wash using a regular shampoo,” says Hazelton. “Leaving the residue can prevent the grays from getting properly coverage during your appointment,” she adds.

The solution? Use a clarifying shampoo (or, at a minimum, lather up twice) the morning of your appointment to ensure that all root concealer products are removed from your strands.

When Should You Wash Your Hair After Dyeing It?

Burns suggests waiting 48 hours before the next shampoo. "This will give enough time for the hair cuticle to calm down a bit and seal in the color," she says.

Summary: So, Should I Wash My Hair Before Dyeing It?

You should always wash your hair before dyeing it if you are coloring it at home; if you've used root coverup or dry shampoo; or if you're getting highlights or balayage done. When in doubt, consult with your stylist before your appointment.

Frequently Asked Questions

Should You Wash Your Hair Before Bleaching It?

Hazelton says no. “It is essential to have dirty hair, or else the bleaching process can be unbearably uncomfortable for many people.” Again, the natural oils act as a barrier between the bleach that’s required to lighten your hair and your scalp.

Can You Dye Your Hair Whether It's Clean or Dirty?

According to Burns, yes, you can. "It’s just the type of dirt you have going on. Hair that hasn't been washed in a day or two with no dry shampoo in it isn't usually a problem. But if you're on day seven of not washing it, you might want to give yourself a good scrub the night before with a clarifying shampoo," she says.

Why Do Hairdressers Wash Hair Before Dyeing It?

"It's specific to the requirements of my client's hair. For example, I might wash their hair before applying a demineralizing pre-treatment or a strengthening service, if the hair needs extra love before being colored. Another difference is, when I wash someone's hair before dyeing it, I know I am getting a good lather and thorough rinse throughout the scalp and hair," explains Burns.

Do Hairstylists Prefer Clean or Dirty Hair for Coloring?

Again, it depends on the type of dirt. "If you just came from the gym that morning but have washed your hair the day before, no worries. I usually go by a two-day limit though, as long as no dry shampoo or temporary root cover up was used," says Burns.

Jenny Jin

Beauty Director

Oversees all beauty content at PureWow
Has over a decade of experience in writing and editing, both in print and digital media
Produces 'Youngish' newsletter, a guide to beauty in your 30s and beyond

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