To care for our natural hair, it is helpful to know the structure of our hair and how it responds to moisture.
So What is Hair Porosity?
I like to think of my hair as a plant. Plants need hydration to thrive and grow and so does hair.
Hair porosity indicates how well your hair absorbs and retains moisture. In reality, some hair is better at staying hydrated and holding in moisture than others.
There are three categories of hair porosity (Low, medium or high), but first, let’s get into how hair holds in moisture by looking at its structure.
Each strand of hair has three layers and these are:
The Cuticle: Think of this as your hair’s coat. The cuticle is the outer layer of the strand made of cells that overlap. When viewed under a microscope the cuticles look like the shingles on a roof.
The Cortex: This is the middle layer of the hair strand and the thickest layer which makes up most of the hair. The cortex is also the layer with the proteins that determine the natural colour of your hair.
The Medulla: This is the central layer of the hair.
The Levels of Hair Porosity
Your level of hair porosity indicates the structure of your hair’s cuticle layer (the coat).
The three levels of hair porosity are:
Hair cuticles that are close together. This makes it harder for moisture to penetrate the hair shaft.
Characteristics of Low Porosity Hair
– Longer drying time
– Prone to product build-up
– Oils sit on top of your hair
Cuticles that are more open than low porosity hair cuticles and allow moisture to enter the hair shaft. Medium porosity hair is usually easier to maintain and can be coloured easily.
Characteristics of Medium Porosity Hair
– Bounce and elasticity
– Little maintenance required.
Cuticles that are open and widely spaced. High porosity hair can be a result of genetics or hair damage. As the cuticles are open, it is easy for moisture to penetrate the hair shaft, but it also means that it is harder for the moisture to stay in.
Characteristics of High Porosity Hair
– Hair dries quickly
– Hair can be frizzy
– Hair feels dry soon after applying moisturiser
How to Find out your Hair’s Porosity Level
Fill a glass with water and take a strand of your clean hair (without product on it) and place it in the glass of water. After about 3 minutes, check the glass to see how the hair responds.
Low Porosity Hair is likely to float at the top of the glass
Medium Porosity will float to the middle of the glass
High Porosity Hair (open cuticles) is likely to sink to the bottom of the glass.
Another way to test your hair’s porosity is by touch. Run your finger up a clean strand of hair (from end to root). Low porosity hair feels smooth. High porosity hair will feel rough or bumpy as the cuticles are open.
How to Manage Low Porosity Hair
The goal with low porosity hair is to help the hair absorb some moisture.
As it is harder for moisture to penetrate the cuticle, water-based products can be applied as your base, followed by moisturisers such as jojoba oil or shea butter to lock in the moisture.
How to Manage High Porosity Hair
High porosity hair is the hair type that can let in too much water, which can lead to frizz. On the flip side, because the cuticles are open, moisture can leave the hair easily and can cause dryness.
To seal in moisture, anti-humectant products help, whilst also helping to keep excess moisture out.
Genetics or even chemical and heat damage are factors which determine your level of hair porosity. The hair porosity test can help you to find the best products to keep your hair healthy and moisturised.