Personalization of hair care products is one of the most structurally significant trends in the current professional sector. But behind the marketing promise of “custom-made,” there is a far more nuanced formulation reality. What genuinely justifies a “personalized” product on a chemical level? Which actives to vary according to which diagnosis? Hairswiss analyzes the scientific foundations of adapted hair formulation.
Why a Single Formula Cannot Suit All Hair Types
The hair fiber varies considerably from person to person according to four measurable parameters: fiber diameter (from 50 µm for very fine hair to over 100 µm for thick hair), porosity (ratio of cortex lacunar zones to total mass), natural hydration level (dependent on NMF and CEW), and curvature index (from 0 for straight hair to high values for tight curls). These four variables directly determine the needs in surfactants, conditioning agents, and repairing actives.
The Active Variables to Adjust According to Hair Profile
1. The Surfactant System: Adapting Cleansing Power to the Scalp
The choice and dosage of the main surfactant is the most determining variable in a shampoo. A scalp with high sebum production requires an anionic surfactant with low CMC (high detergent power), such as SLES or Sodium C14-16 Olefin Sulfonate. A dry or sensitive scalp benefits from a mild amphoteric-glucoside system. The same fiber can have an oily scalp and dry lengths — a situation requiring a shampoo formulated to clean at the root without depleting the lengths.
2. Conditioning Agents: Cationic vs. Film-Forming
The most commonly used conditioning agents are cationic polymers (Polyquaternium-7, Polyquaternium-10, Guar Hydroxypropyltrimonium Chloride). Their positive charge fixes them electrostatically to anionic keratin, depositing a smoothing film after rinsing. Their selection must account for hair type: low molecular weight Polyquaternium penetrates slightly into the fiber (ideal for fine hair — no weighing down), while modified Guars deposit a thicker film (ideal for thick or curly hair). An excess of cationic polymers on fine hair causes progressive build-up: the hair becomes heavy, dull, and difficult to comb.
3. Repairing Actives: Targeting the Level of Degradation
- Low porosity (healthy or lightly treated hair): preventive actives — panthenol, low molecular weight hyaluronic acid, hydrolyzed silk proteins. These molecules partially penetrate and maintain optimal hydration.
- Medium porosity (colored or lightly treated hair): surface reconstructing actives — hydrolyzed keratin (3,000–10,000 Da), Regenine (Hydroxypropyltrimonium Hydrolyzed Corn Starch), synthetic 18-MEA. They fill cuticle lacunae and slow ongoing degradation.
- High porosity (heavily bleached, weakened hair): low molecular weight penetrating actives (<500 Da) — free amino acids (arginine, cysteine), panthenol, small peptides. Only these molecules can reach the cortex to partially restore mechanical cohesion.
The “Personalized” Formulation in Practice: What Is Possible, What Is Marketing
Online personalization platforms offering shampoos “formulated for you” based on a questionnaire rely on customization of comfort and fragrance actives — rarely on a genuine adaptation of the surfactant system, which remains standardized in most cases. A truly adapted formulation requires a prior hair diagnosis (porosity, elasticity, scalp nature), the selection of a coherent surfactant system, and the choice of actives according to the observed degradation level. This is exactly what the professional does in the salon — with diagnosis-structured ranges, like those available on cliCHair.ch.
What the Professional Must Remember
Personalization is not a marketing argument — it is a chemical necessity. The same conditioning molecule produces radically different effects depending on fiber diameter, porosity level, and technical history. Recommending the right product for the right client starts with a rigorous diagnosis — not an attractive label.
Hairswiss regularly explores the science behind professional hair formulations. Next topic: bipartite conditioning systems — why two-phase products offer more precise active deposition.