What Happens When You Leave Hair Dye In Too Long?

What Happens When You Leave Hair Dye In Too Long?

On a scale of one to ten, finally deciding to dye your hair breaks the scale regarding the excitement and rush of adrenaline that comes with it. Deciding on which color to dye your hair is also an exciting choice to make, especially when it’s your first time trying out hair dye.

But hair dyeing is much more than making a decision or picking a color, you have to do it right so that the chemicals contained in it do not end up causing damage to your hair.

Hair dyeing is a process that involves the changing of one’s hair color as a chemical reaction. Hair dye contains artificial chemical compounds that are used to alter your natural hair color.

Hair dye can be permanent or temporary, this is based on how long it can last after it is applied to your hair.

What Happens When You Leave Hair Dye In Too Long?

What you want to do is try dyeing your hair once in a while when the need kicks in, what you do not want to do no matter what is to leave in the hair dye longer than the instructions recommended. Hair dyeing is a chemical process and when it is not followed accordingly, your hair will suffer from one type of damage or another.

1. It Affects Your Hair Texture

What Happens When You Leave Hair Dye In Too Long?
Source: Stylecraze

Different hair types have varying levels of thickness, all of which are important factors to consider when deciding to dye your hair. Your hair thickness can either be low (fine hair), medium, or high.

If your hair thickness is high or medium, then hair dye can stay in your hair for as long as is on the instructions and even a little while longer before the chemicals begin to affect it negatively.

However, the case is different for fine hair, it is much lighter than the other hair types and needs to be paid more attention to especially when being subjected to a chemical hair treatment or process such as hair dyeing.

For fine hair the risk of being damaged is higher when you leave the hair dye in for longer than usual, sometimes you might even have to rinse out the dye before the time indicated in the instructions when you notice that the color has developed faster than you would have expected, this saves your hair from becoming thinner.

2. Has Negative Effect On High Porosity Hair

 If you didn’t know earlier, you should know now that your hair porosity also plays a vital role in the hair dye process. If your hair has a high porosity, it will absorb more of the hair dye, and faster than others, it continues to absorb the hair dye until it is rinsed out at the end of the process.

This is a huge disadvantage because hair dye contains chemicals that your hair should not be exposed to too much. By absorbing hair dye faster, hair with high porosity is likely to suffer from more hair damage when the hair dye is left in for longer than necessary.

3. Exposes Hair To Toxic Chemicals

Hair dyes need the presence of chemical Ingredients for the hair color to develop. This means that as long as you have decided to dye your hair, you have accepted the risk of hair damage as a result of toxic chemicals when you leave the hair dye in for longer than you have been instructed to.

The toxic chemicals present in hair dye include; ammonia, p-Phenylenediamine, resorcinol, lead acetate, and hydrogen peroxide.

Should You Use Coconut Oil After Dyeing Your Hair
Image: Envato Elements

How long should you leave hair dye in your hair?

You would naturally be asking this question when you’re looking to dye a friend’s hair or dye yours at home instead of a salon, and we’ve got you covered so you don’t make a mistake that will damage your hair in the process.

 When dyeing your hair, you should leave it in for 30 to 45 minutes to be safe. If the color has fully developed in thirty minutes, you can rinse your hair and it’ll turn out great. Make sure you follow the instructions on the product package as well.


Now you know that leaving hair dye in your hair longer than is allowed, is a recipe for hair damage. Any hair procedure that involves chemicals should be carefully followed to avoid hair damage and hair dyeing is one of such procedures.

We all love a good hair dye job, all we have to do to keep it that way is to follow the instructions that come with whatever hair dye you purchase.

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