Quick Answer
Porosity determines how well your hair can absorb and retain moisture. Hair with **low porosity** has an extremely tightly closed cuticle layer that barely lets moisture in. Hair with **high porosity** has wide open cuticles – it soaks up water super fast but loses it just as quickly.
Table of Contents
1. What exactly does hair porosity mean?
The outermost layer of our hair consists of microscopic scales, similar to a pinecone. Porosity describes the condition of this cuticle layer. It determines whether hair care products can even penetrate the hair's interior or if they just remain on the surface, weighing the hair down without doing anything.
Porosity can be genetically determined, but it also changes due to external influences such as heat styling, bleaching, UV radiation, or chemical treatments.
2. The Glass of Water Test: Find out your porosity
To perfectly adapt your routine, you need to know the condition of your hair. Take a freshly washed, dry strand of hair (without styling products!) and place it in a glass of room temperature water. Wait about 3 to 5 minutes and observe what happens:
The hair floats on top: You have **low porosity**. The cuticle layer is so dense that water cannot penetrate to pull the hair down.
The hair slowly sinks to the middle: You have normal, balanced porosity. Congratulations, your hair absorbs care optimally.
The hair immediately sinks to the bottom: You have **high porosity**. The hair quickly soaks up water through the open gaps and sinks like a stone.
3. Low Porosity: The fortress that needs warmth
If your curls take a very long time to get completely wet in the shower, and products often sit on your hair for hours like a sticky film, it all points to low porosity. Heavy oils or rich butters completely clog this type of hair.
4. High Porosity: The sponge that demands proteins
High porosity hair usually dries in record time after washing, but almost immediately feels straw-like again. Because the cuticle layer is wide open or damaged, moisture continuously evaporates.
These curls love rich leave-ins and heavy creams to mechanically seal the open gaps. In addition, hydrolyzed proteins are an absolute must here: they temporarily settle into the cracks of the cuticle layer and repair the structure so that the hair can retain moisture at all.
Your Hair Care Strategy at a Glance
Do the glass of water test to find out if your cuticle layer is open or closed.
Use light, liquid products. Always use heat (e.g., a thermal cap) when deep conditioning to open the hair for care. Avoid too many proteins.
Focus on protein-rich treatments and rich leave-ins. Seal moisture after styling with a cold-rinse conditioner or hair oil to close the cuticle layer.
Frequently Asked Questions about Hair Porosity
Can one head have different porosities?
Yes, this is very common! Since our ends are much older and have experienced more sun, friction, and brushing than the freshly grown roots, the ends are usually significantly more porous (high porosity) than the roots (low or medium porosity). Therefore, concentrate rich care and proteins mainly on the lengths and ends.
Does porosity change with hair dyeing?
Absolutely. Chemical dyes, especially bleaches, forcibly break open the cuticle layer to change the pigments inside. After a chemical treatment, hair almost always shifts to high porosity and then intensely demands proteins and deep moisturizing care.
What role does water temperature play in washing?
Warm water opens the cuticle layer, cold water closes it. If you have low porosity, it's best to wash with consistently warm water. If you suffer from high porosity, you should definitely rinse out the conditioner with ice-cold water at the end to lock moisture into the hair.
Conclusion
There is no bad porosity – there is only the wrong product strategy. Once you know how your cuticle behaves, you won't throw money out the window on unsuitable products anymore. Give a closed cuticle layer the necessary warmth and mend an open structure with valuable proteins. Your curls will thank you with healthy shine and perfect definition!
