Hair Care

All About Hair Porosity

When hair starts growing from its roots, it is at its thickest. It is least porous.

What is porosity? Porosity is the ability of your hair to absorb (and release) water. Having high porosity hair can be damaging to your hair’s cuticles. Cuticles are like windows on your hair; if they are open, moisture can leave and enter hair easily causing the hair to swell.

Now if the inner cortex of your hair swells, but your cuticles remain the same size, you can see that it could cause some cuticles to fall off and break. Over time, this can cause serious hair damage.


On the flip side, having low porosity hair means water has a hard time getting in and out of the hair because the cuticles are so closed up. This could mean that your hair is not getting the moisture it needs and that oils and creams just sit on the hair (potentially causing build-up).

Circulating the internet is this idea that you can test for your hair’s porosity by putting a strand in a glass of water and watching to see if it sinks or not. If it sinks within 10 minutes according to the test, then it is porous. If it doesn’t, then it’s not.

While it is possible to get accurate results from this test, there are many variables that have to be considered that could affect the results of this test. For instance, if the hair isn’t clean and has some conditioner on it, it could make the hair more likely to sink (and therefore give off a result of “more porous”).

Now there is a technique for measuring hair porosity called gas sorption (J. Cosmet. Sci. 59, 303-315 July/August 2008) that will give extremely accurate results. It is based off a method used to measure pore sizes for catalysts in industry. As you can imagine, having this done professionally would be extremely expensive so the best way to determine your hair’s porosity would be to play around with it and see how it reacts. Below are tips for determining your hair porosity and taking care of your hair:

Low Porosity Hair

If you’ve never dyed and do not over-manipulate your hair, your hair is most likely low porosity. For me, oils and water usually just sit on top of my hair. This means with a little oil my hair tends to shine and most leave-in conditioners don’t work for me.

Pro-tip #1: You can use leave-in conditioner as a de-tangler! I was really sad a leave-in conditioner I bought didn’t work for me but I found that if I wet my hair very well and applied the leave-in, it provided very good slip for me to remove knots and tangles after a week of leaving my hair out (with minimal breakage).

Low heat is your friend. Your cuticles are so packed together that moisture and oil has a hard time getting in. I use my body heat, apply my deep conditioners(mentioned here) and leave it under my shower cap for about an hour so it is able to deeply penetrate.

Use shampoos and conditioners rich in emollients/occulsive agents. They form a protective film over the hair to prevent water-loss.

Coconut oil is the G.O.A.T. I rub some in before my deep-conditions. Some people say it makes their hair dry and crunchy but I’d wager it’s because they might be adding too much. It is best to use it carefully; I use about a dime-sized amount for my hair, rub it between my hands to melt it and apply it all over my hair, concentrating on my ends.


High Porosity Hair

 Your hair could be high-porosity for several reasons: bleaching and dying, genetics, over-manipulation and plain old weathering. Your ends are usually the most porous part of your hair because they are the oldest.

I put coconut oil on my ends to prevent excessive water penetration 4-8 hours before it’s time to wash/deep condition. This allows the oil to seep in deeply and repel water.

Use a (light) protein deep conditioner bi-weekly. Look out for hydrolyzed milk, soy and wheat proteins in your shampoo/conditioners. It has been shown that even at 1% concentrations, these proteins greatly improve the strength of hair. Everything in moderation though, it is possible to have a protein overload, where your hair becomes straw-like because of too much protein. It’s best to limit yourself to one protein source(in your conditioners) to prevent this.

Am I missing anything? What have you found useful for your hair’s porosity type? Share in the comments section below!

0 Did you love this post?

Love to be emailed content like this?

Subscribe then! What are you waiting for?
First Name
Email address