Ever wondered why a product that transformed your friend's hair does nothing for yours? The answer is usually porosity — and once you know yours, hair care suddenly makes sense.
What porosity is
Porosity is how easily your hair absorbs and holds moisture, and it comes down to the cuticle — the shingle-like outer layer of each strand. When the cuticle lies flat and tight, water struggles to get in or out. When it's raised or cracked, water rushes in and out freely (Scientific American).
The float test (30 seconds)
Drop a clean, dry strand of hair into a glass of water and wait a minute:
- Floats on top → low porosity
- Hovers in the middle → medium / balanced
- Sinks quickly → high porosity
Low porosity hair
The cuticle is tight, so products tend to sit on top rather than absorb. Hair can feel coated, takes ages to get wet and ages to dry.
What to use: lightweight, water-based products; apply to damp hair with a little warmth (a warm towel or the heat of a shower helps the cuticle open); avoid heavy butters that just build up.
High porosity hair
The cuticle is raised or damaged, so hair drinks up moisture but loses it fast — leaving it dry, frizzy and prone to breakage. High porosity is often a sign of damage from heat or bleach, though curly and Afro hair can be naturally more porous.
What to use: richer creams and oils to seal moisture in; protein and moisture masks to rebuild and soften; gentle handling; and, if it's damaged, a repair treatment.
How treatments help by porosity
- High porosity / damaged: hair botox and reconstruction rebuild and smooth the cuticle so moisture finally stays in. A smoothing treatment also flattens the cuticle, cutting frizz.
- Low porosity: focus on lightweight hydration and avoiding build-up; smoothing treatments still help manageability.
Whatever your porosity, the goal is the same: a smooth, sealed cuticle that holds moisture. If your hair is high-porosity because it's damaged, start with how to repair damaged hair — or book a consultation in Belfast or Carrickfergus and we'll recommend the right treatment for your hair.
