How long to leave hair dye in? What happens if you leave hair dye in longer?

Hair dyeing culture in today’s day has grown big. With this advancement in the beauty industry, we can choose from a range of hair dyeing colors. From different brands to different colors in the market: choices are multiple.

Also, with this advancement comes many questions and queries. This article focuses mainly on the leave-in time of hair dye. So, if you are thinking about dyeing your hair, then this article serves best for you.

How does hair dye work?

Here is how a hair dye works before we go into the leave-in time of a hair dye. Different types of hair dyes have their own formula and process.

For instance, there are mainly three types of hair dyes. Here are each of them listed.

1. Semi-permanent dye

As the name says, a semi-permanent dye gives its color to the hair, but it does not last long. The dye attaches to the outer layer of the hair shaft but does not penetrate the cuticle layer.

Also, it gives color to the hair disturbing the natural pigment. It mainly occurs because it lacks ammonia. The lack of ammonia makes it less harmful and relatively pleasant smelling.

Leave-in time: Though it is a semi-permanent dye, the leave-in time cannot be longer. The average time duration of a semi-permanent dye is 30-45 minutes. It is the same as the other dye types, but the time may vary depending on the brand.

There are many brands of semi-permanent dyes available in the market. Here are some of them listed below.

2. Demi-permanent dye

As a semi-permanent hair dye, demi-permanent hair dye is also ammonia-free. But, a demi-permanent hair dye penetrates the hair shaft and imposes its color.

It provides very little lift. It is possible because, along with the dye, a developer is added, which allows penetration. Also, the dye lasts longer than a semi-permanent hair dye.

Leave in time: It ranges from 20- 45 minutes depending upon the color you want.

Here are some of the best demi-permanent hair dyes:

3. Permanent hair dye

A permanent hair dye penetrates the hair shaft and goes deep inside the hair cortex. After entering, it reacts with the hair melanin pigment and removes the natural color of the hair. Permanent hair dye lasts longer than other dyes, and also it is harsher on the hair.

Leave in time: Mainly from 30 to 45 minutes.

Here are some of the best permanent hair dyes:

How long to leave a hair dye in?

Various factors determine the leave-in time of a hair dye. There is no hard and fast rule on the time duration. But, it still ranges from the brand of the hair dye to its type.

Most hair dyes are to leave for 30-45 minutes, but it is always a better option to follow their individual brand instructions.

Here is a guide on how long to leave the dye based on brands, types, and dye color.

Type of hair dyeBrandColor
Semi-permanent hair dyeClariolClariol Natural instincts series (Black brown, light golden brown,blonde)
Leave in time: 20 minutes  
  Clariol Professional beautiful collection– Dark warm brown
Leave in time: 15-25 minutes  
 L’Oreal ParisColorista (teal, light pink, indigo,purple)
Leave in time: 30 minutes
 AdorePink teal, cinnamon, jet black, platinum
Leave in time: 15 minutes with heat
Demi-permanent hair dyeWellaAsh blonde, black, dark blonde, Dark gold blonde, Fiery red
Leave in time: up to 20 minutes
 Ion chromeBlue black, dark natural brown, light golden brown , plum, very light golden blonde, very light neutral blonde
Leave in time: 20 to 30 minutes
Permanent hair dyeGarnierGarnier Olia Ammonia-Free Brilliant Color Oil 34 shades
Leave in time: 30 minutes  
 Wella Koleston Perfect ME  Wella Koleston Perfect 15 shades
Leave in time: 30-35 minutes  

What happens if you leave hair dye in longer?

The most common at-home hair color mistake that people make is leaving the hair dye for a longer period.

An extra 5 to 10 minutes will not be that big of a deal. But with longer leave in time, the effects might show up.

Also, these effects differ based on different hair dyes. Here are few listed below.

1. Semi permanent dye

It is an ammonia-free dye and only coats the outer layer of the hair. It makes it relatively milder than the other hair dyes. But, a semipermanent dye is not completely chemical-free.

So, when you leave a semipermanent dye for a longer time, there are chances of very mild damage or none.

But, there won’t be any darkening of the hair color: it will be the same as mentioned in the box.

2. Permanent dye

A permanent dye contains ammonia, hydrogen peroxide, and other chemicals. It makes the dye unsafe to use for a longer period. Listed below are some effects of longer leave in time of a permanent dye.

  • The hair will be over-processed, rough, and brittle. It will somewhat look like a wig.
  • With some dye, your hair color will turn darker but, it is always associated with damaged hair.

What happens if I leave hair dye in overnight?

Hair dyes have a limited time frame for processing. After that, there is no advantage of keeping the hair dye. An overnight leave-in dye does nothing but damage the hair. Listed below are some of the effects.

  • The hair will be weak and, it will break off easily.
  • The hair will turn very rough and brittle.
  • Also, it will be difficult to remove the dye from the hair and the scalp.
  • There are chances of permanent damage to the hair and hair fall problems.
  • There might be itchiness and irritation of the scalp.

What happens if I rinse hair dye before time?

There are many effects of washing hair before time. With this, you will end up getting a color way lighter than what you wanted.

Also, if you are dyeing your dark hair blonde, there are chances that there won’t be any color change at all. So, you will end up wasting the product.

Final Words

The leave-in time of a hair dye is the crucial step in dyeing the hair. Though the average leave in time is 30 to 40 minutes: it is always a good option to follow the individual brand instruction.

As the effects of excess leave-in time and early rinsing time are always there, one should always take precautions. Also, consulting with a professional hairstylist is very much recommended in the case of dyeing hair.