Hair Porosity Explained: How to Tell What Your Hair Actually Needs

If you have ever wondered why a product that transformed your friend’s hair did nothing for yours, porosity is usually the answer. It is the single most useful thing to know about your hair — more useful than curl type — because it tells you how your hair takes in moisture and how well it holds on to it.

What porosity actually means

Each strand is covered in a layer of overlapping cuticles, a bit like roof tiles. Porosity describes how tightly those tiles sit. Lie flat and closed, and water struggles to get in — but once it is in, it stays. Lift and gap, and water rushes in and rushes straight back out.

Some of it is genetic. The rest comes from what your hair has been through: heat, colour, relaxers, bleach and sun all lift the cuticle permanently.

How to test yours

The float test gets passed around a lot — drop a shed strand in a glass of water and see if it sinks. It is unreliable, because product residue and natural oils change the result. These two tests tell you more:

• The spray test. Mist a small dry section with water. Does it bead on the surface and roll off (low porosity), soak in almost instantly (high porosity), or absorb steadily (medium)?
• The drying test. Time how long your hair takes to air dry. Noticeably longer than most people you know suggests low porosity. Very fast drying suggests high.

Low porosity hair

You probably notice: products sitting on top of the hair, a white cast from creams, hair that takes forever to get properly wet and forever to dry, and a feeling of build-up quite quickly.

What helps:

• Apply products to damp, warm hair — heat opens the cuticle.
• Use a shower cap or warm towel over a treatment for 20–30 minutes.
• Work in thin layers, in sections, rather than one thick handful.
• Clarify occasionally so build-up does not block absorption.

High porosity hair

You probably notice: hair drinks product and is dry again by the next morning, frizzes the moment humidity rises, tangles easily, and feels rough if you run a finger up the strand.

What helps:

• Seal. Moisture is not your problem — keeping it is. Follow every hydrating step with something heavier on top.
• Add protein periodically to help fill the gaps in the cuticle.
• Rinse with cooler water at the end of a wash to help the cuticle lie flatter.
• Be honest about heat. High porosity is usually damage, and more heat deepens it.

Medium porosity hair

The easy middle. Hair takes product well and holds a style. The main job is not to wreck it — keep heat moderate, keep protein and moisture roughly balanced, and do not over-treat what is already working.

Matching LushLoxx to your porosity

• Low porosity: Miracle Gro Hair Butter applied sparingly to damp, warm hair — and give it time under a cap.
• High porosity: Keratin Creamy Hair Mask for the protein side, then the Hair Butter over the top to seal it in.
• Not sure yet? The Hair Care Bundle gives you both, so you can find your own balance.

One last thing worth saying: porosity is not fixed across your whole head. Ends are almost always more porous than roots, because they are older and have been through more. Treat them accordingly.