What happens if you leave hair dye in for 2 hours? Nothing good

Hairdresser applies hair dye

If you leave the dye in your hair for two hours, all this will happen to you:

  • You’ll have dry, porous, and weak hair.
  • You’ll have split ends.
  • You’ll have frizz in your hair.
  • Unwanted tones may appear throughout your hair.
  • The color will look dull.


If you want to go straight to how to repair hair damage after leaving the dye in for two hours, click here


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 When you apply a hair dye at home, you may be tempted to leave it on longer  than the manufacturer indicates.

This happens because you forget to control the time or get distracted. Then, when you remember…

You realize you’ve had the dye in your hair for two hours!


On the other hand, this situation  would barely happen. It’s quite unusual for hairdressers to leave your hair dye in for two hours. 

If a hairdresser forgets about you for that long… it may be time to go find another salon.


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In this article, we’ll look at each of the  consequences of leaving the dye for two hours.  But first, I’ll tell you how the dye works. Follow me!

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How do hair dyes work? An expert tells you

Woman with dyed hair

Hair dyes have an exposure time of 25 to 45 minutes according to the brand. This is always indicated on the label and must be respected. Why?


 If you don’t leave the dye in for the right amount of time, (it can be less or more time) the resulting color may not be   the one you expect.

This is how dyes work. Take note:

  • The first 10-15 minutes of exposure, they open the cuticles to deposit the new color.
  • Once the cuticles are open, the color is deposited during the indicated time.
  • When the exposure time expires, the dye stops working,, but its chemicals continue to dry out your hair. They can even cause scalp irritation or allergies.

In short, if you leave the dye in your hair for too long, nothing serious is going to happen. Really?


Sure,  your hair won’t fall out and you won’t get bald, but you’ll damage your hair.  Of course, you can avoid that if you comply with the time indicated by the manufacturer.

Before continuing, let’s set the difference between permanent and semi-permanent hair dyes.  Permanent hair dyes will cause more damage  if left on for a longer period of time.

On the other hand, semi-permanent dyes don’t have harmful components, such as peroxide. Therefore, they won’t damage the hair fiber. In any case, you shouldn’t leave them on longer than necessary.


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This will happen if you leave the dye in your hair for 2 hours

woman pulling dry ugly hair

You will have dry, porous, and weak hair

The longer you leave the dye in, the more it’ll dry out your hair.

 Your hair will dehydrate because of the chemicals in the permanent dye. 

Since the cuticle is open, it’ll continue to absorb everything that comes its way (good or bad). What else will happen?


Well, it’ll lose water, proteins, and other nutrients.

 In short, your hair will become dry, porous, and weak.  You can think of it as a mathematical formula: TIME = DEHYDRATION.

Yes, we use mathematics in hairdressing, too!


You will have split ends

Split ends appear when the cuticle is damaged.

 Think of your hair like a rope: when it’s new, the strands are attached   but it starts to wear out with time.

When you leave the dye in your hair for 2 hours,  the cuticle starts to break. Then, the famous split ends  that nobody wants.


The hated frizz will appear in your hair

protein overload causes frizz

After leaving the dye in for 2 hours, your hair becomes dry. Do you know what happens next?


Your hair  absorbs microscopic water droplets from the environment  to fill the gap in the hair structure, which leads to the infamous frizz.

Healthy hair has a dense structure and can absorb up to 30 percent of its weight in water. However, dry and damaged hair is porous and absorbs almost twice as much water.


You may find unwanted shades throughout your hair

This will happen only in some cases, according to the color of the dye and the color you had previously. Here are some examples:

  •  If the dye is reddish and you leave it longer than necessary, it may get darker.  You won’t be able to get that bright red you were looking for.


  • If you have bleached hair, you can get highlights that you may not want.

The color could become darker. Even if you have undergone an aggressive process such as bleaching, your hair could break.

So if you have bleached hair, pay close attention to the exposure time of the dye. If possible, go to a salon for treatments.


  • If the dye is black or very dark,  your hair color may look odd. 

When left longer, it darkens too much, and the color will look unnatural.


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Your hair color will look dull and lifeless

When you leave the dye in for two hours,  the resulting color isn’t pretty. Instead, it turns dull and lifeless. 

That is, the dye isn’t aggressive or damaging for your hair, but you must respect the exposure time.


How to repair damage after leaving hair dye in for 2 hours?

As I said at the beginning, you could avoid the damage by following the manufacturer’s instructions. But there is always something we can do to repair the damage from leaving the dye on too long, and this is no exception.


Here are 6 tips to repair your hair after leaving the hair color in for 2 hours:

Attractive woman shows coconut halves

  • Avoid flat irons and excessive heat for a while.

If you’re going to blow-dry your hair, don’t forget to apply a heat protector. You can also use the cool function on your hair dryer. [/su_list]


  • Use sulfate-free shampoo so that it isn’t so aggressive.


  • Use nourishing masks once a week


  •  Use a moisturizing conditioner  every time you wash.


  • Trim damaged ends.


  • You can apply oils on your hair, such as coconut oil. It’s my favorite for these cases.

Leave it on for 40 minutes, wash, and that’s it! Shine guaranteed!


Conclusion: nothing good will happen if you leave the dye in for 2 hours

As we saw in this article, it’s best to respect the exposure time of the dye. If you leave it longer than 2 hours, your hair will look dry, damaged, and frizzy.


Try to go to the salon if you have any doubts or,  you can implement my tips to start repairing what was damaged. 

I hope you can fix it soon and get your hair looking amazing again!

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