Porosity. It’s a term you see all over natural hair tutorials, posts, forums, and products. But you’d be forgiven if you’re still not sure what it means or why you should care about it.
In this post we’ll try to give you an easy to follow guide on what porosity is, how to figure out how porous your hair is, and what that means for your hair routine.
What is it?
When trying to understand hair porosity, it helps to think about the structure of a strand of hair. Hair is made up of 3 major parts:
The inner core (medulla) ; outer proteins (cortex) which determine factors like your hair colour, texture, curl pattern, thickness. And a protective outer layer called the cuticle, which is the focus of porosity.
The cuticle layer is made up of protein-based, scale-like layers that open and close to allow moisture, chemicals and other ingredients to pass through the layer. Its main responsibility is to protect the cortex, by letting moisture into the strand, and making sure that the moisture stays there.
How open the cuticle layer is determines how easy or difficult it is for moisture to pass in and out of the hair strand. This level of openness is what we’re referring to when we talk about porosity.
Why is it important?
For people along the spectrum of curls, maintaining a healthy cuticle is particularly important. As we all know, retaining moisture is key to strong, healthy, curly hair, and the key to retaining moisture is a healthy cuticle.
When the cuticle is healthy, it helps to protect hair from damage by heat, chemicals and manipulation (from excessive styling). Learning about your hair porosity helps you understand how to keep it healthy so it’s strong enough to prevent damage to your hair.
Types of porosity
If your hair has low porosity, the scales in your cuticle lay flat against your hair strand, so that moisture does not pass easily in or out through the layer. Low porosity hair does not easily absorb moisture, but once absorbed, moisture stays in the hair strand.
For people with medium porosity hair, your cuticle layer is looser, allowing moisture to pass through, and maintaining that moisture within the cortex.
If your hair has high porosity, the cuticle layer is raised and difficult to close. This means moisture passes too easily in and out of your hair without being retained.
How to test porosity
There are different tests that can help determine how porous your cuticle layer is. Each has pros and cons, and we encourage you to try different methods as well as keep an eye on how your hair reacts to water, products, and care methods.
It is best to test freshly washed hair with no products. Test strands from your hairline, nape, crown and temple as different sections of your hair may have different levels of porosity.
The Slide Test
Place a tiny strand of hair between your thumb and forefinger. Holding it from the end, slide your fingers up towards your scalp. If your fingers slide smoothly, your cuticle is closed and you have low porosity. If your hair feels rough on the way up, this means that your cuticle is lifted and you have high porosity.
The Float Test
Take a few of strands of clean hair and drop them into a bowl of room temperature water. Watch it for 2-4 minutes. If your hair sinks immediately, it has absorbed the water quickly and has high porosity. If your hair is still floating after 4 minutes, it has low porosity. If your hair is sinking slowly, you have medium porosity.
The Wet Test
Spray a small section of hair with water and watch how your hair reacts. If it gets wet very quickly, your hair has high porosity. If it takes a long time to soak through, or you see beads of water sitting on top of your hair, your hair has low porosity.
The Dry Test
Keep an eye on how long it takes for your hair to dry naturally. If it dries quickly, your hair is high porosity. If it takes hours to dry, you have low porosity hair.
What does this mean for me?
Low Porosity hair
While your hair is great at retaining moisture, this also makes your hair prone to product build-up, which can leave it feeling heavy and stiff. You need regular clarifying washes to remove product build-up.
Low porosity hair needs moisturisers that are rich in emollients such as jojoba oil and coconut oil. Use lighter products such as hair milks that are easy to absorb and won’t leave your hair feeling heavy or greasy.
Use protein-free conditioners with humectants such as glycerin or honey. When deep conditioning, you need heat to help open up your tightly bound cuticle.
For best results, apply products to wet hair when cuticles are most open and ready to absorb.
High Porosity Hair
Hair with high porosity loses moisture just as quickly as it absorbs it. Retaining moisture is your main goal, so it’s important to avoid shampoos with sulphates and other harsh chemicals, use leave-in conditioners, moisturisers and sealers.
By layering these products, you help to close the openings in your cuticle, so your hair can keep the moisture its absorbing. Heavy hair butters can further protect your hair from losing moisture.
Often, highly porous hair is a result of heat or chemical damage, so incorporating protein treatments in your regimen is important for helping to repair your hair.
Protein treatments are usually advised to be used monthly. You may find, that once your hair is stronger and healthier, you won’t need as much protein, so you can update your routine accordingly.
Deep conditioning should be done with every wash (if this sounds exhausting, remember you don’t need to wash your hair as often as people with low porosity hair). Adding moderate heat can help you hair to absorb the moisture it needs.