Is it really necessary to adapt your hair care routine to your hair’s porosity?

The hair porosity is a concept in hair care that remains poorly understood. It describes the fibre’s capacity to absorb and retain water, alongside applied ingredients. Porosity stems from the structure of the cuticle, the hair’s outer layer that functions as a protective barrier. When the cuticle is closed and smooth—its scales, or cells, are well aligned—porosity is low. If the cuticle is open or damaged, porosity is high, altering how hair responds to treatments. Low-porosity hair tends to repel water and ingredients, hindering their uptake, while high-porosity hair absorbs active ingredients but loses them at the same rate due to a weakened cuticular barrier.

Porosity affects how hair responds to hydrating, nourishing, or styling treatments.

While hair porosity has become a popular concept, it is only one factor among many influencing the health and appearance of hair.

Hair texture, sebum production at the scalp and scalp health are important. The hair type and texture are determined by genetic and molecular factors that influence shape, diameter and strength. For example, you should know whether your hair is straight, wavy or curly and whether it is thick or fine before building a routine. Coily hair and hair with pronounced texture require special care because of increased sensitivity. Studies have shown that this hair has the lowest hydration levels due to its high apolar lipid content. The different follicle curvatures of coily hair make it more fragile and prone to dryness.

We also recommend considering your hair growth rate and density to plan cut frequency and set realistic expectations for length and volume, factors independent of porosity. Hair growth rate varies between 0.5 and 1.5 cm per month among individuals. Another factor is sebum production. For oily scalps, weekly use of purifying shampoos can help extend intervals between washes and keep hyperseborrhea. In contrast, those with a relatively dry scalp will opt for hydrating shampoos rich in glycerin or plant oils to compensate for low sebum production.

The condition of your scalp is also an important factor to consider, as it forms the environment in which your hair grows and develops. A healthy scalp promotes the growth of healthy, resilient hair. If your scalp is irritated and shows itching or redness, it may be appropriate to choose soothing treatments and gentle shampoos free of harsh sulphated surfactants that could exacerbate irritation. Ingredients such as aloe vera, the panthenol or oats can help care for sensitive scalps.

When you build your hair care routine, hair porosity should not be the main criterion: choose formulas matching your scalp’s condition (oily, dry, irritated) and your hair type (straight, fine, textured).

Note : If you still wish to consider your hair porosity when refining your hair care routine, some principles can help. For low-porosity hair, with a tightly closed cuticle, we recommend light, water- or hydrosol-based formulations. These penetrate the hair fibre where heavy vegetable oils or rich occlusive products cannot. For high-porosity hair, we recommend treatments rich in film-forming agents, which can create a protective barrier around the hair and fill the gaps in the cuticle.