What is hair porosity? – Here’s Why it matters.

What is your hair porosity?

Your hair porosity determines the extent to which your hair absorbs moisture and hair products. It can be affected by several factors such as your genetic predisposition, damage to the hair stem and the use of certain hair care products. For an effective hair care routine, it is helpful to know your hair porosity. That way, you can find the right hair care products and techniques for your natural hair.

Hair structure

To understand your hair even better, we will first take a closer look at the structure of your hair.

The hair cuticle

The hair cuticles are the hard outer layer of your hair strands. These are small scale-like cells and are made up of keratin (a protein also found in nails and skin). To give you an idea of what these look like, you can think of overlapping roof tiles. Or better yet, the scales of a fish. Like the scales of a fish, our hair cuticles serve to protect the inner structure and these help keep your hair strong and healthy. Therefore, the thickness and number of layers of your hair cuticles, affect the porosity of your hair.

Generally, the hair cuticles lie flat against your hair strands making your hair look shiny and healthy. When your hair is damaged, the cuticles will straighten out leading to dry, brittle and sensitive hair.

💡 Did you know that frizzy hair has fewer cuticle layers than other hair types and is therefore more susceptible to damage?

The cortex

The cortex is the middle layer of the hair strand and is located between the medulla (inner layer) and the hair cuticles (outer layer). In addition, this is also the thickest layer of your hair. The cortex contains pigment cells that produce melanin and determine the color of your hair.

The medulla

The medulla is the soft, central layer of your hair strand and consists of cells that contain air spaces. The medulla is not present in all types of hair. It is often the case that fine or thin hair have no medulla at all.

The 3 types of hair porosity

An image that shows what a hair strand looks like from up close when they have high, normal or low porosity hair

The porosity of your hair can be divided into three groups: high, medium and low porosity. The “category” you fall into is determined by the structure of your hair cuticle.

High porosity

If you have hair with high porosity, it means that your hair cuticles are further apart and they are open. The holes and openings in the cuticle make it easy for moisture to get in but also to get out. You can recognize hair with high porosity by the following characteristics:

  • Your hair dries (usually) quickly, Your hair is prone to frizz
  • Your hair often feels dry

Average or “normal” porosity

Hair with medium porosity has hair cuticles that are not too far apart and are slightly open. This is ideal because your hair can absorb moisture tightly but not release it right away.

You can recognize hair with medium porosity by the following characteristics:

  • Your hair is easy to style
  • your hair absorbs color well
  • your hair looks healthy, shiny or glossy
  • it doesn’t take too long for your hair to air dry.

Low porosity

Hair with low porosity has hair cuticles that are close together and closed. This makes it difficult for moisture to enter the hair; on the other hand, it is also difficult for moisture to leave the hair. You can recognize hair with low porosity by the following characteristics:

  • Your hair takes a long time to dry,
  • Your hair is resistant to coloring and other chemical processes
  • Your hair is prone to product build-up on the scalp

Keep in mind that your hair porosity is more of a spectrum, rather than a catergory. Someone with type 4 hair and low porosity, will look different than someone with straight hair and low porosity.

What determines your hair porosity?

The porosity of your hair is influenced by your genes. In addition, it is important to know that the porosity of your hair can also be influenced by external factors such as,: heat on the hair (straightening and blow-drying), chemicals on the hair, over-washing and the use of aggressive products. These can damage your hair over time which increases the porosity of your hair. So keep in mind that your hair can change porosity over time.

How to determine if your hair has high, low or medium porosity?

There are different ways to determine the porosity of your hair.
The best known way is the float test, better known as “The Float Test:” Then there is also the strand test and the spray bottle test.

The float test

Take a strand of hair from your hairbrush or hair comb. Make sure the hair is clean so that hair products or dirt do not affect the results.

Fill a glass with water and place a lock of your hair in the glass of water.
After 2-4 minutes, see if your hair floats or sinks in the glass.
If your lock of hair quickly and completely sinks to the bottom of your glass, you have high porosity. If your strand of hair continues to float in the middle of your glass, you have medium porosity. If your strand of hair still floats to the top of your glass, then you have low porosity.

The hair strand test

You can also determine porosity by feeling over a strand of hair. Hair with low porosity will feel smooth because the hair cuticles are flat. High porosity hair will feel rough and bumpy because the hair cuticles are open.

The spray bottle test

Finally, there is the spray bottle test. This is a slightly lesser-known method, but you can use it as well. Take a section of your hair and spray it with water. If you notice that your hair absorbs this quickly, then you have high porosity. If the water sits for a while before your hair absorbs the water, then you have medium porosity. If it leaves the droplets of water on your hair and is not absorbed, then you have low porosity.

The behavior of your hair

It is important to keep in mind that these tests are not without flaws. Moreover, not everyone finds it easy to determine the porosity of their hair with one test. Therefore, looking at how your hair behaves is what a much better indicator to determine your porosity. Examples include factors such as frizziness, drying time and product build-up. You can then combine this with one of these tests.

What does hair porosity mean for my hair routine?

Hair porosity helps you look for the right methods and products for your hair routine. Here are some tips to get you started:

High porosity

Because of the openings and lifted hair cuticles, it is important to use methods that retain moisture in your hair. So the goal is to ensure that moisture stays in the hair. So make sure to include nourishing and moisturizing products in your hair routine! When you rinse your hair in the shower, you can use cold water to close your hair cuticles. Another tip that can help you retain moisture is to use products with formulas that have a lower ph balance. The acidity helps close your hair cuticles. A common example is the apple cider vinegar rinse.

Medium porosity

This porosity has no trouble absorbing and retaining moisture. This makes it easier to care for your hair. That doesn’t mean you should neglect your hair, though! Get hair products that nourish your hair and cleanse your hair regularly. Alternate hydration and protein to keep everything in balance.

Low porosity

Because low porosity hair has a hard time allowing moisture to penetrate the hair, it is important to use methods that raise the cuticle so that moisture can penetrate and will stay there. Unlike high porosity, the goal here is to get moisture into the hair.

Use heat and steam to open the cuticle. You can wear a hair cap when you condition your hair to further nourish your hair. Use the steam from your shower to give your products a better chance to penetrate your hair. This combined with products that contain humectants is a good way to keep your hair well moisturized. It is also important to use heavy products sparingly, as build-up can weigh hair down and make it harder for moisture to penetrate. If you often put heavy products in your hair, it is important to wash your hair adequately.