Information about high and low porosity hair:

There’s an important part of this whole, curly girl thing, that often gets overlooked. Why? Because it can get...kind of complicated.

This thing I’m talking about is porosity. What is porosity? It’s how well your hair absorbs and retains moisture.

When I think of porosity I like to think of the word porous, like a sponge, or...cake, yes, let’s use cake. I could really go for some cake now actually...

Personally, I like to think of Tres Leches cake. Why? Because 1) I LOVE tres leches cake and 2) when you make tres leches cake you poke holes in the cake. These holes help the cake absorb the milk. The less holes, the less milk that can really get absorbed. Some milk will get in, but most will just sit on top. Too many holes, and the cake will become oversaturated with milk. Now, that may not be a bad thing with Tres Leches, but it’s not so great when it comes to your hair.

Similar to our delicious cake, the more openings (called cuticles) in our hair strands, the easier it will be for moisture and product to be absorbed...but also the easier it will be for that moisture and product to get out. This is what we call high porosity since the hair is very porous.

Opposite that, the less openings in our hair strands, the harder it is for product and moisture to be absorbed. More product will sit on the strand of hair without being absorbed; however, whatever the hair does absorb will remain soaked into the hair for a longer period of time. This we call low porosity, since the hair is not very porous.

What does this look like?

As mentioned above, the openings in our hair strands are called cuticles. With high porosity hair, the cuticles are raised more frequently, leaving more openings in between cuticles for product to enter the hair strand.

With low porosity, the cuticles more frequently lie flat, leaving fewer entrances/openings for product to enter the hair strand.

How can I figure out my porosity?

As mentioned above, the openings in our hair strands are called cuticles. With high porosity hair, the cuticles are raised more frequently, leaving more openings in between cuticles for product to enter the hair strand.

With low porosity, the cuticles more frequently lie flat, leaving fewer entrances/openings for product to enter the hair strand.

A common way to figure out your porosity is to do the water test. To do this test you:

    1) take a piece of clean, product-less hair and drop it into a cup of water.
    2) push your hair below the water surface to break the surface tension. If you don’t do this you will not get a proper indication of your hair porosity as your hair will automatically float on top of the water (think of how a bug can float on top of the water in a swimming pool).
    3) Wait 5 minutes.
    4) If your hair floats you have low porosity. If you hair sinks you have high porosity. If your hair sits in the.  
        middle of the cup you have medium porosity.

Another way to test is to run your fingers up your hair strand from tip to root. If your hair feels rough, your hair is high porosity. If your hair is smooth you have low porosity.

Lastly, a more subjective way to tell your porosity level is to pay attention to how long it takes for your hair to dry after the shower and how long it takes to absorb product. The faster your hair dries and the more product it absorbs, the higher your porosity. The more times it takes, the lower your porosity.

It is important to note your hair can change porosity over time. Damaged hair is typically high porosity since heat and chemicals raise your hair cuticle. As you transition your hair, you may find the porosity change to medium or low.

So, what does this mean for styling?

Porosity affects what types of products you should look for, how often you will need to clarify, and potentially, what kind of cast you get from products.

If you have high porosity hair, you will need to moisturize and deep condition your hair more frequently since your hair is constantly losing moisture. Once or even twice a week is recommended. Butters and oils are typically okay as your hair will absorb most of it. Ingredients like apple cider vinegar can adjust the pH of your hair and help your cuticle lie flat. At the end of styling, it will also be helpful to seal your hair with an oil.

If your hair is damaged from heat or chemicals, you will also want to factor in occasional protein treatments.

If you have low porosity hair, you will want to avoid products that build up easily, such as oils and butters. You will also need to clarify more frequently to get rid of all the product sitting on top of your hair. Deep conditioning weekly with a heat cap may help open your hair cuticle to allow moisture to enter your hair strand.