Understanding your hair's porosity level — whether it's low, medium or high — is key to effectively managing your locks.

That's why we've taken a deep dive into what hair porosity is and the science behind it, how to test which type you have, and most importantly, how to treat each level to ensure your hair remains healthy, radiant and full of life.

What is hair porosity?

Hair porosity is basically your hair's ability to absorb and retain moisture. To understand this concept, let's delve into the structure of your hair.

Your hair is composed of three main layers:

• The cuticle — Think of the cuticle as the outermost layer of your hair. It's made up of tiny scales that overlap like shingles on a roof, and it shields the inner parts of your hair.
• The cortex — The cortex is the middle layer, containing proteins that give your hair its strength, colour, and texture. It's like the structural foundation of your hair.
• The medulla — The medulla is the soft, innermost layer.

Porosity largely revolves around the behaviour of your hair's cuticle. There are three primary levels of hair porosity, including: 

• Low porosity — Hair resists moisture due to tightly closed cuticles, often causing water to bead on the surface.
• Medium porosity — Hair strikes a balance, allowing for optimal moisture absorption and retention, resulting in manageable styles.
• High porosity — Hair readily absorbs moisture but struggles to retain it, often leading to dryness, frizz, and brittleness.

Factors that can affect hair porosity

Just like your hair type and texture, various factors can influence your hair's porosity. Here's a rundown of what plays a role in determining whether your hair is low, normal, or high porosity:

Genetics

Your genetic makeup largely dictates your hair's natural porosity. If your family tends to have hair that soaks up water like a sponge, you might have inherited that trait.

Chemical treatments

Chemical processes like hair colouring or perming can alter your hair's porosity. These treatments can lift and open the cuticle, making it harder for your hair to retain moisture (high porosity).

Heat styling

Frequent use of heat styling tools, such as straighteners and curling irons, can also impact your cuticles, potentially leading to higher porosity levels over time.

Rough handling of your hair

Rough handling, excessive brushing, and using fine-toothed combs can damage the cuticle, potentially increasing porosity.

To learn more, read our guide on the ways you’re damaging your hair and how you can stop it.

How to test your hair porosity

Understanding the type of hair porosity you have is crucial for maintaining its health and appearance. Here are some ways you can test your hair porosity:

1. Look for the characteristics of each

You may have low porosity hair if: 

• Your hair products don't absorb easily 
• Your hair feels dry and rough
• Your hair tangles easily
• Your hair takes a while to get completely wet
• It takes a long time for your hair to air dry 

You may have medium porosity hair if: 

• Hair products absorb reasonably well, leaving your hair moisturised without feeling weighed down.
• Your hair is easy to style
• Your hair looks healthy and shiny

You may have high porosity hair if: 

• Your hair feels dry 
• Your hair gets frizzy, especially during summer 
• Hair products are quickly absorbed into your hair, but the moisture doesn't last long
• Your hair breaks easily 
• Your hair dries rapidly after washing

2. The float test 

An easy way to understand your hair porosity is using the float test. Simply take a few strands of clean hair and drop them into a bowl of water. Then, observe how the hair behaves:

• Low porosity — If the hair floats on the water's surface, it indicates low porosity. The tightly sealed cuticles prevent water absorption.
• Normal porosity — Hair that sinks slowly to the middle of the water suggests normal porosity. The cuticles allow some moisture absorption without excessive loss.
• High porosity — Hair that sinks quickly to the bottom of the bowl indicates high porosity. The cuticles are open, leading to rapid moisture absorption and loss.

3. The slide test

Take a single strand of hair and slide your fingers up the hair shaft, starting from the ends toward the scalp. Pay attention to how the hair feels:

• Low porosity —  If your fingers glide smoothly and encounter minimal resistance, your hair likely has low porosity.
• Normal porosity — If you feel a slight resistance but can easily slide your fingers along the strand, your hair is of normal porosity.
• High porosity — If you feel a rough, uneven texture and encounter significant resistance, your hair probably has high porosity.

4. The spray bottle test

Mist a small section of clean, dry hair with water. Observe how the hair reacts:

• Low porosity — If the water beads up and sits on the hair's surface without being absorbed, your hair has low porosity.
• Normal porosity — If the water is absorbed at a moderate rate, your hair's porosity is considered normal.
• High porosity — If the water is quickly absorbed and the hair feels damp, your hair is likely of high porosity.

How to treat low porosity hair

If your hair porosity is down to genetics, you, unfortunately, won't be able to change it. But there are some things you can do to make it healthier and easier to manage.

1. Opt for water-based hair products

With low-porosity hair, sealed cuticles can block moisture from getting to the inner layer. That's why picking water-based products is essential, as these light formulas break through the barrier, giving your hair the hydration and nutrients it craves. Heavy products can lead to buildup, making your hair appear greasy and worsening the challenges of dryness and brittleness.

2. Use warm water when deep conditioning

When deep conditioning your low-porosity hair, wet your hair with warm water first. This gentle heat can help open the cuticles slightly, making it easier for moisture to absorb during conditioning. You could even use a shower cap once the conditioner is added to enhance the effect.

3. Use a silk pillowcase

Unlike rougher fabrics, silk causes less friction against your hair, preventing breakage and moisture loss when you toss and turn in your sleep. 

4. Use protein-free conditions

While proteins are often beneficial for hair health, the tightly sealed cuticles of low-porosity hair can resist the larger molecules. This may leave the product sitting on the surface rather than penetrating, therefore, it's best to choose protein-free conditioners for better moisture absorption.

How to treat high porosity hair 

1. Use heat protectant 

High porosity hair has wider-spaced cuticles, making it more prone to damage. When exposed to tools like hairdryers, straighteners, or curling irons, the excessive heat can weaken the already vulnerable cuticles. That's why using a heat protectant spray or oil is essential before applying any heat. This layer acts as a barrier, preventing excessive moisture loss and minimising the risk of breakage or hair loss.

2. Choose conditions that contain butters and oils

To combat the quick moisture loss in high-porosity hair, opt for conditioners enriched with nourishing butters and oils. These ingredients provide deep hydration, helping to smooth and fortify your hair's structure.

3. Avoid hot water when washing your hair

Hot water can cause the cuticles to open excessively, stripping away the already limited moisture. Stick to lukewarm water during hair washes to maintain the natural moisture balance and prevent further drying.

4. Get regular trims

The wider cuticles of high porosity hair make the shaft fragile and, therefore, more prone to split ends and breakage. Regular trims help manage these issues, keeping your hair looking healthier and preventing damage from travelling up the hair shaft.

5. Manage frizz

High porosity hair is more prone to frizz due to its open cuticles that allow moisture from the environment to be absorbed quickly. To manage frizz, use anti-frizz products, serums, or leave-in conditioners specifically designed to seal the cuticles and prevent excessive moisture uptake.

Learn more about FUE Clinics

While there isn’t a direct correlation between hair porosity and hair loss, low and high-porosity hair is more prone to external damage. This could potentially contribute to breakage, hair thinning, and even bald patches. 

And there are many other reasons you may be losing your hair, from genetic conditions like pattern baldness and alopecia areata to stress and medical conditions.

At FUE Clinics, we specialise in treatments for alopecia, and our team of experts is here to provide you with personalised guidance. Check out our guide to learn if you’re the right candidate for a hair transplant. 

Get in touch today or take a free online consultation. Or, head over to our FAQs for more information.