What is permanent hair dye?
In the world of hair coloring, there are various technologies designed to meet every need. Among them, permanent hair dye remains the most popular choice due to its long-lasting results and its ability to provide full coverage. But how does it actually work, and how does it differ from other types of hair dye?
Permanent hair dye
Permanent hair color works deep within the hair shaft to permanently change the hair’s color. Unlike temporary hair colors, which deposit dyes more on the surface, permanent hair color involves a reaction within the hair itself. Permanent hair color is formulated to open the hair cuticles and allow dyes to penetrate deep into the hair shaft. This reaction, known as oxidation, permanently alters the hair’s pigmentation by creating new colored molecules within the keratin itself. This is why the color does not fade with repeated shampooing: the dyes are truly fixed within the hair.
Permanent Hair Dye vs. Tone-on-Tone Hair Dye: The Key Differences
The main difference lies in the longevity and depth of action:
Tone-on-tone hair color works without penetrating deeply into the hair shaft. The dyes settle on top of the natural color, resulting in a temporary effect. The color gradually fades with each wash, lasting about 6 to 8 weeks. However, this type of hair color does not lighten the hair and only partially covers gray hair.
Permanent hair color works by penetrating deep into the hair shaft to permanently alter the hair’s natural pigmentation. This process relies on opening the cuticle scales, allowing the colorants to bind deeply within the hair cortex. Thanks to this mechanism, permanent hair dye offers long-lasting results, remains intact until the roots grow out, ensures 100% gray coverage, and allows for lightening up to two shades above the natural color.
The Benefits of Permanent Hair Dye
Complete coverage of gray hair
That’s the main advantage of permanent hair dye: it completely covers gray hair, even the most stubborn strands.
Long-lasting wear
The color withstands repeated washing and retains its vibrancy for weeks. Only regrowth at the roots will require a touch-up, usually every 4 to 6 weeks depending on how fast your hair grows.
Hair Structure: The Essential Role of Keratin
To effectively care for your hair, it is essential to understand its structure and the factors that ensure its vitality and strength. Hair has a complex structure, consisting of different layers and specific proteins that give it strength, elasticity, and natural beauty. Understanding this structure helps us better grasp the mechanisms that protect the hair shaft from external aggressors and appreciate the importance of proper care in maintaining its vitality and shine every day.
The Structure of Hair
Hair is a complex structure composed mainly of keratin, a fibrous protein that accounts for about 95% of its composition. This protein gives hair its strength, elasticity, and resistance to external stressors.
Hair is made up of three main layers:
- The cuticle: an outer layer composed of flat, overlapping cells, it acts as a protective barrier against physical and chemical damage. Responsible for the hair’s texture and flexibility, the cuticle also protects against moisture. Its integrity is essential to the quality of the hair, as it is particularly vulnerable to external aggressors (UV rays, pollution, chemical treatments).
- The cortex: a middle layer composed of keratin fibers, the cortex is responsible for the hair’s strength, elasticity, and texture. It is also in the cortex that melanin pigments are found, which determine the hair’s natural color.
- The medulla: the central layer found mainly in thick hair.
Keratin: Your Secret to Strong Hair
Keratin, the main component of the hair shaft, is a highly resilient protein composed of amino acids that is essential for the formation of disulfide bonds, which ensure the hair’s cohesion and strength. Any alteration to its structure—caused, for example, by chemical or heat treatments—can weaken the hair, making it more susceptible to breakage and damage.
When it comes to hair coloring, its action involves opening the hair cuticles to allow the colorants to penetrate, thereby ensuring an even result. It is therefore essential to use a suitable treatment after each coloring session, such as our treatment enriched with plant-based keratin, which helps strengthen the hair shaft and close the cuticles by providing this essential protein to the hair.
Taking Care of Your Scalp: The Key to Healthy Hair
Although often overlooked in hair care routines, the scalp is actually the key to strong, thick, and healthy hair.
At KERANOVE, we view the scalp as a complete ecosystem, whose balance directly determines the beauty of the hair.
The Scalp: The Source of Our Hair
The scalp is much more than just the foundation on which hair grows. Rich in blood vessels and sebaceous glands, it contains twice as much water as the skin in general, which underscores the importance of moisturizing this area to maintain its balance and proper function.
The scalp microbiome
The scalp is also home to a community of microorganisms that live on its surface. This microbiome supports the skin’s barrier function and acts as a protective layer to help maintain theskin’s integrity.² Studies have shown that scalp conditions are strongly correlated with thescalp’s commensal microbiome.³ Many factors, such as heat, pollution, hair care products, and the composition of the microbiome, can cause an imbalance in the scalp (dysbiosis)4. This can manifest as a sensitive scalp and excesssebum2.
Scalp sensitivity is a common condition, particularly amongwomen.5 In fact, 44% of French people reported having a sensitive scalp, with this percentage being higher among women than amongmen.6 A healthy scalp and a balanced microbiome are therefore essential for vibrant, healthy hair.
Prebiotics for a Balanced Scalp
Prebiotics are very important for skin health: their role is to nourish the beneficial bacteria in the microbiome in order to strengthen theskin’s natural protective flora.
That’s why our Kéranove hair coloring treatment includes a serum enriched with prebiotics to rebalance, hydrate, and soothe the scalp after coloring.
The scalp is a complex biological environment, and its balance is crucial to the quality and vitality of the hair shaft. An approach based on an understanding of how it functions, its hydration, and its microbiome allows for targeted and effective action. By incorporating proven active ingredients, such as prebiotics, it becomes possible to sustainably support the scalp’s balance and optimize the conditions necessary for healthy, vibrant hair.