What Happens If You Leave Hair Dye on Too Long

One of the most common questions that our readers ask is – what happens if you leave hair dye on too long? Well, the reason for the question is not far fetched. With the increase in the number of homemade and DIY strategies, you should know the appropriate duration to leave hair dye. 

If you wash the dye off too soon, you will just waste the chemical. On the other hand, if you leave hair dye too long, it may affect your hair color or texture. In this article, we explain factors to consider and the ideal duration for hair dyes. 

What to know before you dye your hair by Samantha Aguirre

Factors to consider on how long do you leave hair dye in 

The recommended duration for leaving hair dye depends on the factors listed below: 

Normal color of your hair

Before buying chemicals and accessories for styling your hair, you should consider its authentic color. As your hair grows, its natural hue may interfere with that of the dye. It is advisable to check the dye’s packaging material for the resulting coloration after its application. Moreover, select the one that gels well with your hair’s normal tint. 

Amount of Gray Hair 

If you have a significant amount of gray hair due to aging or genetics, you may leave hair dye on for extended periods. This step is necessary to thoroughly cover the strands. Moreover, you will need an enduring dye to paint the hair perfectly.  

Your Hair’s Present Tint 

What is your hair color at the moment? This knowledge will affect the choice of hair dye to use. For instance, if your current hair shade is darkish, you cannot apply a lighter tint immediately. Rather, you will remove the old dye and restore your hair to its normal color. Afterward, you may apply the new dye and may leave hair dye for a longer duration. 

Hair Sponginess 

Sponginess refers to the capacity of your hair to soak up water easily. Hair with high sponginess takes up the dye without stress. You may end up spending less time. However, if your hair has low sponginess, the duration will likely increase. 

Your Hair Thickness 

All hairstyles for girls have one of these three thickness ranges – fine, moderate, and dense. Fine hair often possesses tinier strands. Thus, you need minimal chemicals and time to change its coloration. Moderate hair is the most common and it requires about 45 minutes for thorough dyeing. People with dense hair need more chemicals and must leave the hair dye on for a longer duration. 

How long to leave semi permanent hair dye in 

Several hairstyles often require dyes to enhance their texture and appearance. The term “semi permanent” refers to dyes that lack stronger constituents such as ammonia and peroxide. As a result, you can wash them off with minimal issues. Also, they do not change the shade of your hair completely. 

Quite often, semi permanent dyes only coat the outer portion of your hair. This way, your hair follicles remain intact. Moreover, if you leave the hair dye on for an extended period, consider adding salt to the water. It softens the scalp and hair strands for easier removal. 

How long to leave blue hair dye in?

It takes several hours to transform your hair completely, even if you visit a hairdresser. Doing it yourself might take even longer. You need to wash your hair and remove any stale coloring it may have. It may be necessary to bleach before applying dye. Also, you have to dedicate sufficient time for drying after washing, bleaching, and dyeing. 

Moreover, be careful when applying the blue dye because of scalp damage. If your hair is too dry, the damage may be pronounced. Try moisturizing your hair for easier application. 

How long to leave black, permanent hair dye in?

For those asking “what happens if you leave hair dye on too long”, especially if it is black, ensure you stick to under 45 minutes. Follow the manufacturer’s instructions to avoid losing your hair’s beautiful and shiny appearance. Besides, it will not make your hair darker or more appealing. Rather, it gives a weird look. 

Frequently Asked Questions

Does leaving hair dye in longer make it darker?

What happens if you leave hair dye in longer than recommended?

Does hair dye get darker the longer you leave it in?


If you want to give your hair another stunning look, applying dyes is a good method. However, if you are wondering about “what happens if you leave hair dye on too long”, you may retain your hair but lose its shine. It is advisable to always follow the producer’s instructions to play safe. Factors that will affect the duration you leave hair dye in include thickness, sponginess, gray portion, and color. Moreover, the whole process takes lots of time.