Does Leaving Hair Dye In Longer Make It Darker?

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We’ve all had that urge to buy a box of hair dye and color our hair. Many people successfully do so at home, with great results! But things can go wrong, too, with disastrous implications. You should know what you’re doing!

If you are new to dyeing your hair, it’s easy to screw up, especially if you’re bending the rules. 

Does leaving hair dye in longer make it darker? The short answer here is yes, leaving hair dye in your hair longer will make the result darker. However, that’s not the only thing that could happen to your hair. 

It may seem like a good idea, but it could severely dry out the hair.

Let’s talk about that below. 


Why Does Leaving Hair Dye In Longer Make It Darker?

When dyeing your hair at home, it is important to carefully follow the instructions and not go off the script! Depending on the dye that you choose, you might be instructed to leave it on your hair for up to 30 minutes. 

We all can’t just sit down and wait forever. Sometimes we do other things to pass the time, and that could lead us to forget that the time is up! And we’ve left the hair dye on our hair for far too long. 

Oh oh.

By doing that, the hair becomes exposed to the hair dye solution longer than it should have. The ingredients have more time to react with your hair strands. The end result will be a darker color than you intended. 

When dyeing your hair at home, it is important to carefully follow the instructions and not go off the script!

However, with the longer exposure of the hair to the chemicals, you’ll get a darker color… and your hair may also become quite brittle because it was overly processed. 

Hair dyes aren’t known to cause your hair to fall off, unlike bleach which can cause hair to fall out if left for a long time.

If you are using a semi-permanent hair dye, the chemicals there aren’t as damaging so the hair should still be fine, especially if your hair is healthy. 

With semi-permanent dyes, the color is only saturated on the external layer of the hair. That is why the hair isn’t quite as damaged as compared to other hair dyes. This means your hair won’t fall out, but the color will be darker than intended. 

Now if you are using a permanent dye, then the hair can become brittle and drier.

That’s because the chemicals here are stronger so that they can penetrate the deeper layers of the hair. 

Although the result you get from permanent hair dyes could last longer, they are also made of stronger chemicals. By following the time recommendations on the instructions, you will ensure that your hair is colored without it getting dry and brittle. 

By following the time recommendations on the instructions, you will ensure that your hair is colored without it getting dry and brittle. 

If you leave permanent dyes for far too long, then your hair could get dry, damaged, and dull. It won’t look shiny and healthy anymore. 

Although leaving the hair dye on the hair for a longer time could cause it to be a little darker, there is a limit to how dark it will get.

So if you have a light brown hair dye, don’t expect it to turn into a dark brown color if you leave it longer.

What To Do If You Leave Hair Dye For Too Long?

When you realize that you’ve let the hair dye soak on your hair for too long, rinse it out immediately and follow the aftercare instructions. There is nothing else you can do at this point but check your hair for any damage. 

Sometimes, your hair may get dried because of overexposure to hair dyes. Even if there aren’t any clear signs that your hair is damaged, you should still take precautions when you know that you’ve left the dye for too long. 

Although your hair won’t fall out, it could be more fragile. That means you’d have to take care of your hair properly so that it doesn’t get more damaged. Here are a few things that you should do: 

1. Avoid Heat Styling

It’s exciting to style your hair when it is a different color now but please avoid using heat stylers. They’ll just worsen the problem and damage your hair even more.

The heat from the stylers could further dry up the strands and make them even more brittle. 

2. Keep Your Hair Moisturized

Another thing that you could do to take care of your hair is to keep it moisturized. Use a conditioner or a hair mask regularly to help make them healthier again. 

Biolage Color Last Conditioner | Color Safe Conditioner | Helps Maintain Depth & Shine | For Color-Treated Hair | Paraben & Silicone-Free | Vegan​| Cruelty Free | 33.8 Fl. Oz
  • Color Safe Conditioner: Low pH...
  • Benefits: Color-treated hair often loses...
  • Additional Benefits: This product...
  • Suggested Use: Apply to wet hair and...
  • Color Last Collection: Color Last system...

When you are doing this, make sure to select products that are suitable for color-treated hair so that your hair dye doesn’t fade easily. 

There are hair nourishing products  that you can use on your hair to help make sure that they get what they need so that they become healthy again.

amika soulfood nourishing Mask, 8 Fl oz
  • Deeply hydrates and conditions normal...
  • Packed with nourishing ingredients like...
  • Free of sulfates, parabens, phthalates,...

3. Lessen Frequency Of Washing

You should also lessen the frequency of washing and shampooing of hair, and wash with cool water. That will help prevent hair loss and dry hair too. 

4. Cut The Damaged Ends

The ends of the hair are the parts where it is most prone to damaged. Sometimes, the damage is irreversible and all you can do is cut off those damaged ends. 

When you see white tips on the ends or split ends, you have to get your ends trimmed to get rid of them. Split ends start at the ends but could eventually rise if you don’t cut them off. 

Instead of just having the ends damaged, you’d also be putting the rest of the hair strand at risk if you don’t cut off the damaged ends. 

Written by Kayla Young

Kayla is the founder of LuxeLuminous. She has worked professionally in the tanning industry for years. She has been interested in esthetics since childhood, and has tried every hair, skin, and makeup product ever produced (more or less).