Understanding Hair Porosity | A Complete Guide

Have you ever wondered why some hair products work amazingly on your hair, making it shiny and glossy, whereas other products make it seem greasy or do absolutely nothing for your hair? It’s all down to your hair porosity. You might have heard about the different hair types you can have that will affect how you care for your hair, but hair porosity is also important to know if you want to give your hair the best care possible. We’ll go into everything you need to know about hair porosity and what this means for your care routine.

What is Hair Porosity?

Porosity is a measurement of how well your hair can absorb and hold moisture. The ability to hold moisture is due to the makeup of each hair strand. To understand this better, let’s take a closer look at hair strands.

It’s important to note that hair strands are made up of three parts:

1. Cuticle: This it the outermost layer of the hair. The cuticle is made up of overlapping layers that protect the inner layers of hair.
2. Cortex: The middle layer of the hair is where most of the natural colour and strength is.
3. Medulla: The innermost layer of hair is soft.

For hair to be in peak condition, moisture is needed in the cortex. If the cuticle layer is lifted, moisture can get inside easily to the cortex but can’t be retained. However, if your cuticle is closed, moisture can’t get to the cortex easily. Caleb Backe, hair care expert at Maple Holistics explains this:

“In a nutshell, hair porosity refers to your hair's ability to absorb moisture. Some hair types can absorb moisture better than others. Hair porosity is usually split into 3 categories: normal, low and high porosity. For example, straight hair tends to have a smoother hair cuticle, and this means that it can absorb moisture more effectively, while tightly coiled or curly hair has a low porosity because the curls create bends in the hair shaft and make it difficult for the hair to absorb moisture efficiently.”

Types of Hair Porosity

As stated by Caleb Backe, there are three types of hair porosity – low porosity, medium porosity, and high porosity. Each level has varying levels of absorbancy and characteristics:

• Low Porosity Hair:
  • Closed cuticles
  • Difficult for moisture to penetrate
  • Resistant to treatments and styling
  • Any moisture absorbed is maintained
  • Tends to be smooth and shiny
  • Can experience build-up

• Medium Porosity Hair:
  • Slightly raised cuticle layer
  • Inbetween high and low porosity
  • Allows for moderate absorption of moisture
  • Retains moisture well
  • Can hold styles
  • Resistant to damage

• High Porosity Hair:
  • Open cuticles
  • Absorbs moisture easily
  • Unable to retain the moisture it absorbs
  • Can be frizzy
  • Sometimes occurs due to damage

Although high porosity can be the result of damage to hair from styling and heating, it can also be a natural porosity. It’s also important to note that none of the porosity levels are “better” than the other. All can be found naturally. However, knowing your hair porosity can help you care for it correctly so it will look and feel its best.

What Influences Hair Porosity?

Hair porosity is largely due to genetics. Curly hair tends to have a naturally higher hair porosity than straight. However, a few external factors can cause your hair cuticles to lift, causing higher porosity. This is normally due to damage and can be permanent. These factors include:

• UVA and UVB damage (sun exposure)
• Frequent use of heat (straightening, blow drying, etc.)
• Bleaching
• Air pollution

How to Test Your Hair Porosity

Finding out your hair porosity can help you to care for it properly. There are three main tests for discovering your hair porosity:

The Float Test

1. Ensure your hair is clean (shampoo and rinse)
2. Fill a glass with water
3. Once your hair is dry, take a single hair (cut it from your hair; it doesn’t need to be full-length)
4. Drop this hair strand into the water

How your hair behaves in the water will tell you the porosity:

• Low Porosity Hair will float on the top before sinking
• Medium Porosity Hair will float somewhere in the middle of the glass
• High Porosity Hair will quickly sink to the bottom of the glass

The Spritz Test

1. Ensure your hair is clean (shampoo and rinse)
2. Let your hair dry
3. Take a small section of hair and mist it with a spray bottle

How the water behaves on your hair will tell you the porosity:

• On Low Porosity Hair, the water will bead up
• On Medium Porosity Hair, the water will sit on the hair for a few minutes before being absorbed
• On High Porosity Hair, the water will quickly be absorbed

The Slip Test

1. Ensure your hair is clean (shampoo and rinse)
2. Let your hair dry
3. Take a strand of hair and slide your fingers up towards the scalp

How your hair feels will indicate the porosity:

• Low Porosity Hair will feel smooth
• High Porosity Hair will feel rough with small bumps
• Medium Porosity Hair will be somewhere inbetween

Caring for Your Hair

Once you know your hair porosity, you can learn how to give it the best care, what products to use, and what to avoid. All of which will lead to your hair looking and feeling the best it can. Kate Ross, hair specialist from Irresistable Me says:

“Understanding your hair porosity is key to choosing the right hair care products and routines. Whether your hair has low, medium, or high porosity affects how well it absorbs and retains moisture. Knowing your porosity level can help you tailor your regimen to ensure your hair stays healthy, hydrated, and manageable.”

Caring for Low Porosity Hair

As already stated, low porosity hair doesn’t absorb moisture well but will retain any moisture it does absorb.

Key characteristics of low porosity hair include:

• Hard for water to saturate when washing
• Takes a long time to air dry
• Hair products will sit on top
• Looks shiny
• Less prone to becoming tangled
• Can be difficult to style
• Often looks the same wet as when dry

The main challenge with this level of porosity is that it can be prone to build-up. Therefore, you should choose light products that will help to moisturise your hair. Our general care tips for this type of hair are:

• Avoid heavy products such as butters and thick oils
• Deep condition when needed and apply heat (such as a warm towel) to open the cuticles and encourage absorbtion
• Clarify regularly to avoid build-up of products
• Use low suds shampoos
• Avoid oils such as coconut that seal the cuticle
• Avoid high acidity ingredients such as apple cider vinegar

Caring for Medium Porosity Hair

Medium porosity hair is also known as “normal porosity”, but this doesn’t mean you can just do what you like; it still needs to be cared for in a specific way.

Key characteristics of medium porosity hair include:

• Fairly easy to maintain and style
• Doesn’t get wet immediately, but only takes a few minutes to absorb water.
• May look stretched out when wet
• Retains moisture well
• Can be prone to dryness, build-up and over-moisturisation
• Doesn’t dry quickly or slowly

The main challenge with this level of porosity is that you need to find the right balance to keep it healthy. You don’t want to use products that are too light or too heavy, getting it wrong can cause dryness or build-up. Our general care tips for this type of hair are:

• Use proteins and moisturisers for balanced hair care
• Don’t use proteins daily
• Avoid overloading with products
• Deep condition regularly and use gentle heat (such as a warm towel) to help open the cuticles
• Clarify regularly to avoid build up
• Avoid excessive heating or colouring and always use heat protection when heating
• Don’t over-wash

Caring for High Porosity Hair

High porosity hair can occur naturally or through damage. With a loose cuticle, it will quickly absorb and lose moisture, so hydration is key for caring for high porosity hair.

Key characteristics of high porosity hair include:

• Often frizzy
• Absorbs water and products quickly
• Can become very dry and dehydrated
• Hair products will sit on top
• Can look dull
• May have a course texture
• Often struggles with volume
• Breaks easily
• Air dries very fast
• Looks stretched when wet
• Easily over-moisturised

The main challenge with this level of porosity is that it can be prone to dryness. Therefore, heavier products that penetrate the hair are good for this level. However, it’s important not to over-moisturise too. Our general care tips for this type of hair are:

• Use heavy, moisture-rich products such as butters and thick oils
• Keep moisture in with oils that seal the cuticle, such as coconut oil
• Avoid heat styling and harsh treatments; when styling with heat, ensure to use a heat protector
• Regulalry deep condition
• Use leave-in conditioners
• Include proteins in your hair care routine
• Finish washing with a cold rinse to close the cuticles

Can you Change Your Hair Porosity?

As your natural hair porosity is due to genetics, you cannot change this. However, using heat to style and harsh chemicals, as well as exposure to other external factors, can cause damage and give you a higher hair porosity. If damage has caused high hair porosity, nourishing and repairing your hair can help return it to its natural porosity (but some damage can be permanent).

Rather than trying to change your hair porosity, the best thing to do is to learn what level your hair is and then how to give it the best care. Once you know your hair porosity, we have a huge range of hair care products that’ll help you give the best care to your hair.