Hair Color

How Long To Leave Hair Dye In? Tips For The Perfect Shade

If your hair turned out a different hue than you had in mind, it could be because you didn’t give the hair dye enough time or maybe even let the dye stay longer than it should have.

Written by Tripti Mohan

On Jan 29, 2024 – 6 minutes read

How Long To Leave Hair Dye In

Hair dyeing is no less than an art. Whether you do it at home or a salon, allowing the correct processing time is as important as choosing the right color and product. If you have had trouble achieving the hue you had in mind, it could be because you didn’t give it enough time or even let the dye stay longer than it must. Here, we provide you with every information you would ever need regarding how long to leave hair dye in your hair. Check it out!

Hair Dye Types And How Long Do You Leave Hair Dye In?

 How Long To Leave Hair Dye In At Home

Does the type of hair dye affect how long it takes to stain? Absolutely! 

The type of hair dye you choose is based on the texture of your hair and the color you want to achieve. This, in turn, decides how long it should be applied to your hair. Here are the most common kinds of hair dyes(1) and the time for which they are recommended to be left.

Permanent Hair Dye

Permanent hair dyes have strong chemical compositions with ammonia and hydrogen peroxide. This ensures that the color enters deep into the hair shaft and lasts longer. A permanent hair dye or hair bleach can normally stay from six to eight weeks. The processing time of such dye is about 30-45 minutes, depending on the brand. Always be cautious and take the instructions on the product seriously. Leaving the hair dye for longer than the stipulated time can potentially damage your hair and, sometimes, even your scalp.

Demi Permanent Hair Dye

Is your hair pretty porous? Then, you may not need hair dyes with many oxidative agents like ammonia. Demi-permanent hair dye is meant only to penetrate lightly into your hair shaft. Such hair dye can be effective within 10 to 30 minutes, and the color would remain for up to 20 hair washes. 

Semi Permanent Hair Dye

Semi-permanent hair dye usually refers to the semi-natural hair dyes that you use. It doesn’t contain strong chemicals. The dye doesn’t penetrate into the hair cuticles and just colors from the outside. How long should you leave this hair dye in? Just about 5 to 30 minutes. The color fades with every wash and lasts in condition for about 4-5 weeks.

Temporary Hair Dye

Temporary hair dye gives you the desired hair color for only up to one wash. Obviously, the color doesn’t seep into the hair shaft and, therefore, has a processing time of as little as 5 to 10 minutes. Leaving it for a longer time will most likely not make much difference.

Henna and Plant-based Dye

Prefer going the natural way? You must be using henna or a plant-based dye, then. It is close to impossible to achieve a black color with these dyes. You usually get an amber-to-brown shade of hair. Since the dye is made of leaves, roots, etc., it takes longer to stain. You may have to leave it for at least one hour for the hair to dye. It can be left for up to 6 hours, depending on the shade you want. The color can very well last for 4 to 6 weeks.

What Is The Processing Time Of Hair Dye?

Hair Dye Processing Time

How long you leave your hair dye in is the same as the processing time of the hair dye. This time is measured from when you finish applying the hair dye all over your hair. In the above section, we told you how the processing time differs depending on the type of hair dye and the intensity of color that you want. Let’s see what other factors affect the processing time of hair dye.

Factors Affecting Processing Time of Hair Dye

  • Hair Health: Has your hair gone through a lot of heat and chemical treatment already? Then, most likely, they are pretty damaged, which means the cuticles are wide open for the dye to stain easily. The processing time to color unhealthy hair is much less than that of fresh, healthy hair. You didn’t see that coming, did you?
  • Hair Texture: Even if your hair is healthy, if its texture is porous, the color is absorbed easily. Therefore, processing time is less in this case, too. Your salon expert should be able to help you understand if your hair is porous or not. On the other hand, if your hair is coarse and has a thick cuticle layer, it may take much longer for the dye to act.
  • Developer Strength: The developer’s strength varies depending on the type of hair dye that you choose. If your dye contains a strong developer like in permanent hair dye, then the processing time is less. How long to leave hair dye in before rinsing is mentioned on the box of your product and should be taken into serious consideration.
  • Brand of the Dye: The formulation of every dye is different for different brands. The composition of the ingredients would determine how long to leave the hair dye in.
  • Desired Color Intensity: What is the intensity of the color that you’d like for your hair? If you want only a subtle change in color, the processing time would be less. However, if you are looking for bold, vibrant colors or colors that need to lighten your natural hair color by several shades, it would require pre-bleaching and the processing time would be much higher.
  • Grey Hair: Are you wondering how long to leave hair dye in for grey hair? You might need much longer. The dye pigments need longer to penetrate into gray hair.

Avoiding Over-Processing

Processing time for each type of hair dye is stipulated for a reason. It is, hence, essential that you stick to it. If you think you can achieve a darker color by leaving a dye for longer than its recommended processing time, then you are mistaken. Most artificial colors do not stain after a particular time. If the maximum processing time is given as 45 minutes, you must understand that there won’t be any difference in color after that point.

On the other hand, leaving your hair exposed to the chemicals for longer can cause more damage to your hair cuticles. An itching or tingling feeling could mean that the chemicals are starting to affect the skin on your scalp too.


1. Can I leave hair dye in for 15 minutes?

Yes, most hair dyes are safe to be left for 15 minutes. If you want more vibrant coloring, you may need to leave it for another 10-15 minutes, at least.

2. Should I shampoo my hair after dying it?

No! Apply the dye on clean, dry hair. After applying, wait for 3-4 days before using shampoo on your hair. 

3. Why does my hair go so dark when I dye it?

Your hair could be porous and need less time than mentioned in the product. Try reducing the processing time next time.

4. Can leaving hair dye on too long cause hair loss?

Yes. Letting your hair be exposed to the chemicals for too long may lead to hair loss later.

5. Can I add conditioner to hair dye?

Yes, you may add a small amount of conditioner while applying hair dye. However, using too much of it may dilute the composition of the dye.


Hair dye should be left on your hair depending on your hair type, product, and desired color. Please remember that everything we mentioned here is mostly generic and that you must refer to the guidelines on the product you use for best results. Hopefully, we have cleared all the doubts in your mind, and now you won’t have to worry about how long to leave your hair dye in.

  1. FDA. (n.d).Hair Dyes. [Online] Available at:

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Tripti is your go-to guide for all things skin and hair. She is a trusted beauty consultant who offers personalized recommendations and expert tips to enhance your natural beauty.

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