How Long Does Demi Permanent Hair Color Last? Demi-permanent hair color will fade gradually, lasting between 12 – 24 shampooings. The longevity length will depend on various factors, including hair porosity, type of water, and shampoo brand.
The Science behind Demi Permanent Hair Coloring
Understanding how demi-permanent hair coloring works and how it differs from permanent hair coloring will help explain longevity.
Permanent hair color, which is hair color that permanently changes the hair color, achieves this through the addition of a developer used to open up the cuticle of the hair so that the dye can penetrate the hair shaft, permanently altering its color.
Demi-permanent hair color is more translucent than permanent hair color and does not require the same strength developer. The hair cuticle opens slightly to allow a small amount of dye to wrap around the cuticle rather than penetrating it fully. This means that the dye will eventually fade with each washing.
Hair Porosity Affects Demi Permanent Hair Color Longevity
Hair porosity describes how porous the hair is. Some people have highly porous hair, which retains water. The reason for this is that in highly porous hair, the hair shaft’s cuticle is raised. This can cause a problem when coloring your hair because this hair type often colors unevenly. Adversely, hair with low porosity has a hair cuticle that is flat and closed, making it difficult to absorb hair color.
Because hair porosity will affect your demi-permanent hair coloring treatment results, it will also factor into how long your hair color will last.
Temperature and Type of Water Could Affect Longevity of Hair Color
Hard water versus soft water. One is better for your hair. Especially color-treated hair.
Hard water is high in dissolved minerals, especially calcium and magnesium. Wellwater is often hard water. Hard water is not an ally when it comes to hair. Shampoo does not lather as well in hard water, meaning you have to use more of it. It also takes longer to rinse out the shampoo.
Soft water is water that is free of minerals and chemicals. Rainwater is soft water, as well as water that has been filtered. Shampoo in soft water lathers and rinses out easily, meaning you can use less shampoo and rinse for a shorter period. Since shampooing slowly fades demi-permanent hair color, soft water is the way to go.
The temperature of the water matters as well. Hot water will wash out your hair color faster than cool water because hot water opens your hair’s cuticles, exposing your hair color. Rinsing your hair with cool water after shampooing will close the cuticle and help to seal in color.
Shampoo Can Make or Break Your Hair Color
The harsh chemicals found in many shampoos can begin stripping your hair of its demi-permanent hair color from the first washing. Avoid any products that contain sulfates. Sulfates strip color from the hair. Also, avoid clarifying shampoos once your hair has been colored. Clarifying shampoos also strip dye from hair. Your best bet is to use products that are specifically designed to protect color-treated hair.
Resources – “How Long Does Demi Permanent Hair Color Last?”
- Matric – Difference between Temporary, Permanent, Demi-Permanent, and Semi-Permanent Hair Color
- Redken – What Is Hair Porosity and What Does It Mean for My Hair Concerns?
- United States Geological Survey – Water Science School – Hardness of Water
- “Culligan – Soft Water vs. Hard Water: What’s the Difference?
- Matrix – 26 Tips to Help Protect Color Treated Hair & Keep It Looking Fabulous
