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Let’s Talk Hair Porosity: Here’s What You Need to Know

BY Laura Casciola

It’s time for a chat about hair porosity. We know about “pores” when it comes to our skin, but what about our hair?

Turns out that hair, mainly the cuticle layer of the hair shaft (aka the outermost layer), has pores in it. This unique feature determines how well your mane absorbs and retains moisture.

Of course, there’s more to it than this short summary. Hair porosity is a concept worthy of a longer explanation, so let’s dive in.

Hair Porosity: Your Hair’s Ability to Absorb Water

If absorbing water sounds important, it is. When we talk about hydrating, moisturizing, and conditioning your hair, we have to keep in mind that all hair has different abilities in doing and maintaining all of those functions.

So, why do we have different hair porosity levels? There are two main factors: hair type and level of damage.

Let’s Start With Hair Type

A hair type is more than just a look and feel. It’s actually in your DNA, and in the geometry of every strand of hair and its cuticle layer (the outer layer of your hair shaft). Straight, wavy, curly, and coily hair types have different geometries, and therefore, different hair porosity levels

Here’s how your hair cuticle relates to your hair’s porosity level

As you can see, it’s completely normal for you to have more or less porous hair than your BFF. Wondering how the different hair types rank on the porosity scale? Check out this mini-list:

  • Straight hair is the least porous. Its fibers have cuticles that are tightly aligned, meaning there’s less opportunity for moisture to go in and out.
  • Wavy and curly hair is more porous. The hair cuticles lay more loosely on the fiber, so there’s a bit more opportunity for moisture to go in and out.
  • Coily hair is the most porous. Its cuticles are loose on the hair shaft, so moisture is absorbed and lost rapidly. 

Regardless of the products you put in your hair, the geometry of your hair fibers affects the amount of natural oils that traverse from root to tip.

For instance, the geometry of coily hair slows the movement of oils down the strand of your hair. Oils may be absorbed close to the scalp but are unable to make their way to the ends (which might never get the moisture they need), leading to dryness and frizzy hair. 

On the contrary, less porous hair might allow oils to glide down the fiber without being fully absorbed. As a result, the remaining oils could give off the appearance of hair looking greasy.

Feel like your hair is somewhere in the middle of these breakdowns? There are a few simple hair porosity tests to uncover your hair’s porosity level.

The Water Droplet Test

Take a few strands of your hair and put a drop of water on them. Does the water go right through your hair or sit on top of it? If the droplet absorbs into your hair pretty quickly, you have high porosity hair. If it sits there for a while, you have low porosity hair.

The Float Test (aka the Strand Test)

Drop a few strands of hair into a glass of water. After a few minutes, less porous hair will remain floating at the top, while more porous hair will sink to the bottom. If your hair floats somewhere in the middle, that means you have normal porosity hair.

What About Damage and Hair Porosity?

Damage — the wear and tear (literally) of brushing, styling, using heat products and dyes on hair, and simply hair growing and experiencing weathering — affects porosity. That said, most of us have at least a bit of damage. The more damage, the higher the hair porosity. 

In fact, if your mane regularly experiences chemical processing and/or heat-styling, chances are that it’s highly porous — and more prone to breakage (yikes!). This is why we always stress the importance of using a heat protectant before touching the hot tools, and why air-dry trumps blow-dry. Of course, nourishing hair products can also help tamp down some of the damage to strengthen your locks (more on that later). 

Now you know the porosity of your hair based on your hair type and damage level. What can you do?

How the Right Haircare Products Can Help

To understand how the right haircare products can help your tresses, let’s break it down by the type of hair porosity.

Low Porosity Hair (Less Porous)

  • You’re able to wash your hair more frequently.
  • You might use a light conditioner, focusing mainly on the ends to downplay product buildup.
  • Volume could be something you’re looking for, especially if you also have thin, fine strands. Add it as a hair goal or find products that help create lift at the root.

Medium Porosity Hair (Normal Porosity Hair)

  • Remember, the more porous your locks, the more your hair needs conditioning from the roots to the ends.
  • Even though your hair generally holds styles well, you still want to protect your ‘do. Curl definition might be a good hair goal for you — you want to see shine bands (a more uniform curl pattern is a sign of healthy hair).
  • Seek out products with anti-frizz (especially if your hair is exposed to lots of humidity).
  • Color your hair? Wash it less. Water, particularly at high temperatures, is the biggest culprit for fading your expensive dye job. Use cold water as much as possible.

High Porosity Hair (Even More Porous)

  • Use a deep conditioning treatment, like a hair mask, at least once a month.
  • You’ll want to use a co-wash to gently cleanse hair while protecting the natural oils on your fibers.
  • You might regularly use leave-in treatments to tame the tangles and frizz.
  • It’s best to use a clarifying shampoo at least once every week or few weeks, rather than days, to downplay the product buildup without drying out your fibers.
  • Consider a hair steamer. When using a hair mask, wrap your hair and then put it under a steamer to allow the product to penetrate deeply and hydrate your mane from the inside out.
  • Scalp treatments are important too. The geometry of natural hair types (curly and coily hair) means oils build up on your scalp rather than move down the strand. Use a scalp treatment to cleanse. 

Cater to Your Hair’s Porosity Level

When it comes to hair porosity, it’s important to learn your hair porosity level, assess your hair damage, and find products and hair goals that help your hair get the moisture it needs. 

Take our hair quiz to find the products custom-made to your hair. Function of Beauty’s haircare range is free of sulfates, parabens, and other potentially harmful ingredients to put your best locks forward.