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What Happens If I Accidentally Washed My Hair Before Bleaching?

A happy young black woman after getting a hair bleaching treatment on clean hair by a hair colorist.

Hairstylists, hair colorists, and home-coloring enthusiasts agree that bleaching dirty hair is much safer than deciding to bleach freshly washed hair. But what happens when you forget and wash your hair anyway?

Can you bleach wet hair? What happens if you wash your hair before bleaching it?

If you ever find yourself in this position, don’t panic! In this article, we’ll take a look at what happens when you wash your hair before bleaching it.

We’ll also give you plenty of tips on how to minimize bleaching damage, so make sure you read until the end.

What Happens If I Accidentally Washed My Hair Before Bleaching?

Hair experts agree it’s better to bleach your hair a few days after your last wash. When you bleach dirty hair, your hair’s natural oils, produced by your scalp, protect your hair and skin from chemical damage.

Alternatively, washing your hair before you bleach it increases your risk of damage.

You’ll also be more likely to experience discomfort and scalp irritation when bleaching wet hair. Even gentle, sulfate-free shampoos expose your scalp and strands to bleach’s damaging effects.

If you accidentally wash your hair before you plan on bleaching it, it’s better to just wait. Wait a few days and lighten your hair after your natural oils have built up again. 

A black woman at the mall picked up some hair products to bleach hair strands using a DIY hair coloring technique.

How Long Should You Avoid Washing Your Hair Before Bleaching It?

Try not to wash your hair for at least three or four days before your bleaching session. That will give your hair’s natural oils plenty of time to coat your strands and scalp.

Bleaching dirty hair (or unwashed hair) is perfectly safe and effective. Slight oiliness won’t affect how the bleach takes, and you won’t have to worry about patchy or uneven color. 

Note: If your hair is caked in product buildup or any thick, gunky substance, this will affect how the bleach ultimately takes. It could leave you with an uneven lightening result. So, if your hair is too dirty, wash it and then wait a few days before bleaching it. 

How to Protect Hair Before Bleaching It

Whether you’ve accidentally washed your hair or are just trying to keep your hair healthy, there are ways you can keep bleach-related damage to a minimum. Here are a few different methods you can use to protect your hair before you bleach it:

Coat Your Strands With Oil

Applying oil to your hair and scalp will result in less overall bleach-related damage.

The oils not only moisturize your scalp and hair, but they also act as a barrier against some of the harsh chemicals in the bleach.

Several oils provide this benefit, but here are a few of our favorites: 

  • Coconut oil
  • Olive oil
  • Argan oil 

Don’t Bleach Your Hair All in One Go

If you plan on drastically lightening your hair, doing it in one go dramatically increases your chances of frying your strands. Break up your lightening treatments into multiple sessions and give your hair time to recover before you lighten it again.

Although it will take significantly longer, breaking your bleaching treatment into several or more sessions will always help to preserve the health of your hair. Better still, you might even decide to leave your hair darker than you initially planned. 

An African American female with dry hair walks to a hair bleaching appointment at a Great Clips location in the mall.

Don’t Skimp on Bleach Quality

Not all bleach powders and developers are created equally. Some countries have strict standards when it comes to manufacturing bleach. For example, bleach made in the United States and Germany is known to be of better quality than China-made bleach.

So, before you bleach your hair, ensure you’re equipped with high-quality products made in a country with tight regulations. Poor quality bleach is harsher on your strands and scalp and can result in unexpected lightening results.

Choose a Weaker Developer When Possible

Typically, developers come in strengths ranging from 10 Vol to 40 Vol. The stronger a developer is, the quicker and more substantially it will lighten your hair.

In addition, strong developers damage your hair more severely. Use the lowest volume developer possible if you want to keep damage to a minimum. If possible, use a 20 Vol or 30 Vol rather than a 40 Vol or 50 Vol. 

Young black female researching purple shampoo and DIY hair dyes using her cell phone while sitting on a park bench.

Apply a Protein Filler

If you have damaged or high porosity hair, a protein filler might be just what you need to keep your hair safe while you bleach it. Protein fillers fill in imperfections, dents, and holes along your hair shaft, which strengthens the strand and helps it absorb the bleach more effectively.

You can either add a protein filler directly into your bleaching mixture or apply it to your strands before you lighten them.

Break Out the Deep Conditioner

Bleaching your hair strips it of moisture and makes it weaker, so you need to increase your hair’s resilience by giving it plenty of hydration. Do a daily deep conditioning treatment the week before your bleaching session.

You can also pair your deep conditioner with heat to make it more effective.

Heat opens your hair’s cuticles, which allows more of the conditioner’s nourishing ingredients to sink into your strands. Just sit under a hooded dryer or wear a heated conditioning cap as you allow the mask to process.

Never Forget Your Strand Test

A day or two before your bleaching session, mix up a small batch of your desired bleach and developer. Apply the mixture to a small patch of skin and a few strands of easy-to-hide hair.

Let the mixture sit for up to 30 minutes, then rinse and check for signs of irritation.

Doing a patch test will help prevent a hair disaster and give you a good idea of what your hair will look like after you finish bleaching it.

You can see whether or not you’ll have to make adjustments and might even decide bleaching your entire head of hair would be too damaging. 

A cute young black female with natural curls styled with a few drops of coconut oil and a low-heat blow dryer.

Dos and Don’ts of Bleaching Hair

Bleach is one of the harshest products you can use on your hair. Luckily, there are ways to avoid some of the adverse effects and keep your hair healthy.

Here’s a list of dos and don’ts to keep in mind throughout the bleaching process. 


  • Do mix 1 part bleach to 2 parts developer.
  • Do protect your skin, body, and surroundings before bleaching. 
  • Do follow the directions on your bleaching kit as closely as possible. 
  • Do prepare for some mild discomfort.
  • Do get your hair professionally lightened if you can.
  • Do deep condition your hair regularly. 
  • Do adjust your bleaching session for your hair type and damage level. 
  • Do keep a close eye on your color progression and rinse out the bleach as soon as your hair is sufficiently lifted. 


  • Don’t wash your hair for at least three days before bleaching. 
  • Don’t use hot styling tools on your hair for at least two weeks before bleaching your hair.
  • Don’t forget to condition and moisturize your hair before you lighten it.
  • Don’t leave your bleach on for longer than the recommended time. 
  • Don’t use harsh or drying products on your hair before or after bleaching. 
  • Don’t forget to protect your strands from sunlight, chlorine, and salt water. 
  • Don’t skip your post-bleach care routine. 
  • Don’t bleach your hair if it’s already dry, brittle, or damaged.
  • Don’t forget to do a strand test before you apply the bleach to the rest of your hair. 

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To sum things up, washing your hair before you bleach it dramatically increases your chances of facing damage and irritation. It isn’t worth the risk, so just postpone your bleaching session if you ever accidentally forget and wash your hair beforehand.

If you can’t avoid it, follow some of the tips we’ve gone over in the article to help minimize damage and keep your hair and scalp safe. We hope this article has answered all your questions and shown you how to avoid bleach-related hair disasters!