Protective cuticle ­regeneration

An ageing population with a desire to look younger has long been the driving force behind the global hair care market1. However, it was not until the release of the two-step hair repair system, Olaplex, that innovation in this category was really pushed to answer current consumer needs. Colouring, washing, drying and styling of the hair is highly emotive, and the cosmetic results can easily be seen, helping to boost confidence or give an immediate feeling of change. With fast-paced fashions and image-driven social media influencing the hair care sector, it is vital to offer protection to hair while allowing consumers to achieve the colour, condition and style that they desire in real time.  

Plex products have focused on building disulphide, hydrogen or salt bonds in the hair following chemical treatments to help maintain strength. However, it is the layered structure of the cuticle that also plays an important role as a protective barrier and promotes the visible cosmetic properties of the hair. The epicuticle is a chemically resistant proteinaceous layer forming the outermost part of the hair. It is covered by strongly bound structural lipids described as the “F-Layer” or “β-Layer”, which represents the outermost covering of the fibre2. This lipid layer has a natural lubricating mechanism and also acts a water repellent. When hair is healthy the cuticle layers remain intact and tightly compacted, helping to protect the cortex and promote minimal loss of hydration.

When the hair is exposed to weathering, it is these first layers that can be harshly affected, altering the porosity of the hair. Porosity describes the ability of the hair to absorb and release water and is directly related to the condition of the cuticle and β-Layer3. If the hair is in good condition, the cuticle is intact and smooth. If in bad condition, the hair may be swollen, the cuticle layer exhibiting raised or even missing scales. The hair’s porosity can be directly affected by different stressors such as friction and physical hair-shaft injury, excessive exposure to sunlight, excessive wetting and chemical and physical processing4. A compromised cuticle layer translates as porous, dull hair that is readily tangled and prone to breakage. Additionally, those with fine hair have less cuticle layers than those with thicker, so cuticle preservation is essential to prevent tangible hair damage. 

During hair processes, such as chemical treatments and thermal styling, exposure to extreme pH or high temperature environments removes some of the protective ‘β-Layer’, causing oxidation of the hair surface and irreversible physicochemical changes in the hair structure. Repeated styling can result in the complete elimination of this protective lipid surface. The hair becomes hydrophilic instead of hydrophobic, and the natural lubricating properties are removed. Although it is widely accepted that chemical, thermal and styling processes are highly damaging, this rarely deters a consumer from either bleaching or straightening their hair. Repair is often an afterthought once the hair begins to appear thinner, matte, more brittle and dry.