Hair Porosity: The Reason Some Products Never Work for You

Have you ever tried a product someone else swears by — only to find it does absolutely nothing for your hair?

The reason is rarely the product itself. It’s porosity.

What Porosity Really Means

Porosity refers to how easily your hair absorbs and retains moisture. It’s determined by the condition of the cuticle — the outermost protective layer of the hair shaft.

When cuticles lie flat and compact, hair has low porosity. When cuticles are raised or damaged, hair has high porosity. This changes everything about how products behave.

Low Porosity Hair

Low-porosity hair resists moisture initially and can become weighed down easily.

Heavy creams and oils often sit on top of the fibre rather than penetrating. Lightweight hydration and balanced cleansing typically perform better.

High Porosity Hair

High-porosity hair absorbs moisture quickly — but loses it just as fast. It often results from colouring or heat exposure.

It typically needs sealing support and structural reinforcement. Strengthening systems like Joico or bond-support treatments like K18 can stabilise fibre integrity, while hydration restores elasticity.

Without reinforcement, moisture alone escapes too quickly.

Before You Replace Everything

Understanding porosity prevents routine overload. It explains why some products feel “amazing” for others and underwhelming for you.

When products match porosity, routines simplify — and healthy hair becomes predictable.

The Real Takeaway

When a product doesn’t work, it’s rarely personal. It’s structural — and structure can be understood.