High porosity hair tends to lack shine and strength compared to healthy hair, and is more prone to hair breakage. In contrast, healthy hair tends to have relatively low porosity, making it highly reflective and shiny [1].
Highly porous hair easily absorbs oil, water, and other products, but struggles to maintain the moisture it absorbs. But what makes hair overly porous, and how can you avoid it? In this article, we’ll explore:
A basic knowledge of your hair’s structure makes it easier to understand porosity. A hair shaft is made up of three layers [1]: the cuticle (outer layer), the cortex (middle layer), and the medulla (inner core).
The cuticles are the first line of defence within your hair anatomy. Each hair cuticle is tiny, transparent, and acts as a protective shell for the inner layers of the hair shaft. They overlap with each other like scales, controlling the amount of moisture, chemicals, and products your hair can absorb.
With high porosity hair, the gaps between cuticles are large. Although moisture can easily enter the hair shaft, it doesn’t stay there long enough to nourish your hair. It quickly passes back out through the cuticle, leaving your hair feeling like straw. This dehydrated hair may be more prone to hair loss from breakage.
Larger gaps between cuticles also leave the inner layers of your hair vulnerable to damage [1]. This leads to the loss of important lipids and amino acids from your hair shaft [1].
Although healthy hair usually has quite low porosity (smaller gaps between cuticles), you don’t want the porosity to be too low. Very low porosity may make it hard for your hair to absorb enough moisture in the first place.
The American Board of Certified Haircolorists defines the characteristics of low vs high porosity hair [2]. Here are the differences you’ll see between the two ends of the porosity grading system:
Very little resistance to combing when wet
High porosity hair is common in older people with grey hair and people with light-coloured hair [3]. It can be genetic, but may also be caused by using chemical products such as hair dye, perming, bleach, or exposure to environmental factors like heat, pollution, and excessive ultraviolet (UV) light [1].
These factors can damage your cuticles, causing them to separate and create gaps. These gaps make your hair more porous than it was originally and more prone to hair loss from breakage.
There’s a quick way to test your hair porosity using nothing but a strand of hair and a glass of water. It’s not a true science, so it may not be the most accurate method, but it might give you some indication of how porous your hair is.
How quickly your hair sinks to the bottom is a good indicator of your hair’s porosity [4]. This is what your results mean:
Not getting clear results from this test? There’s another way you can try.
Using a dropper or mister, cover a section of dry hair in water droplets. The results give an indication of how porous your hair is:
If you have highly porous hair, the goal is to make it less porous. This will give it more shine, prevent frizzy, broken hair, and help it retain moisture.
To start with, there are several lifestyle changes that can help prevent and reverse highly porous hair. These include:
High porosity hair often benefits from heavier products that can help lock moisture into the hair shaft. Any products that reverse or prevent cuticle damage can also reduce porosity. Here, we’ll look at some of the best products to keep your hair moisturised.
Research suggests several plant-based oils may help to improve hair porosity [1]. Here are some examples:
One study found hair treated with coconut-based oils helped protect hair from damage during washing and made it less porous [3]. It also retained its colour better than untreated hair.
A 2022 study [3] explained how washing with surfactants (cleansing agents) that diffuse into your hair can cause proteins in the hair to dissolve, increasing the cuticle gap size and making it more porous.
This study measured these changes using scientific tools and found that coconut oils reduce damage by limiting how much a surfactant could affect the hair’s inner structure.
It did this by creating a protective layer, stopping hair proteins from being washed away. Coconut oil-treated hair stayed stronger, maintained its colour better, and had less damage than untreated hair.
A 2021 study explored the effects of milk thistle oil on hair damage [5]. Researchers found that after applying milk thistle oil and then coating the hair in dye, the hair treated with milk thistle absorbed less dye than untreated hair. This suggests milk thistle helped reduce hair porosity.
Hair also became stronger after applying milk thistle oil. Researchers also tested hair shininess, but there were no differences in gloss between treated and untreated hair.
A 2020 study investigated peanut oil as a product to reduce hair damage and porosity [1]. After applying peanut oil and then coating the hair in dye, treated hair absorbed less dye than untreated hair. Therefore, peanut oil appeared to reduce hair porosity.
A 2020 study published in the Asian Journal of Beauty and Cosmetology studied the effects of peanut oil on hair [1]. They treated bleached hair with different amounts of peanut oil (0%, 6%, 9%, and 12%).
After heating the hair, they measured changes in strength, shine, and colour. Researchers found that:
Research suggests hair can be made less porous by filling gaps between cuticles with shampoos rich in amino acids [6]. Shampoos that cleanse your hair without drying it out are recommended for highly porous hair. Some suitable products include:
Check out our shampoo advice for getting the most out of your shampoo, and how to give yourself a thorough scalp and hair detox.
Disclaimer: The products mentioned on this page are for reference purposes only and have been selected based on online reviews and user-reported results. Wimpole Clinic does not endorse or guarantee the effectiveness of these products.
Deep conditioners may help reduce porosity by creating a protective layer and sealing gaps between cuticles. You can make your own deep conditioning treatment if you want to save some cash and have total control of what goes into it.
Here’s a recipe for your own deep conditioner to repair damaged hair at home. You’ll need a bowl, spoon, whisk, resealable container and:
To make the conditioner:
To use the conditioner, cover damp hair in the mixture and let it sit for 3-5 minutes. Then wash and condition your hair as normal. The oils in the mixture help to coat your hair strands, which protects them during washing, reduces porosity, and stops important hair proteins from being washed away.
If you don’t have the appetite for DIY mixtures and you’d prefer to buy a conditioner that’s ready to go, here are some of the top products for highly porous hair:
It’s time to wash your high-porosity hair and you want to keep it as healthy as possible. Follow these simple steps for shinier hair with less breakage.
If you’re doing all you can but you still have hair that’s dry, rough and frizzy, a professional trichologist can help. These hair doctors can identify the cause of your damaged tresses through a detailed lifestyle assessment and diagnostic trichology tests.
Dry, brittle hair can sometimes be caused by underlying medical conditions, such as a thyroid disorder [7]. A trichologist can identify when something doesn’t seem right and refer on to a specialist doctor for further investigation.
Want to learn how to regain smooth, shiny hair? Find your nearest hair clinic location and book a free consultation today to get started.
High porosity hair may appear frizzy, dull, and break off easily. It gets tangled and is more prone to breakage, so you might notice more hair loss in the shower. It absorbs product quickly but struggles to retain the moisture, so after washing it looks and feels dry.
Fixing high-porosity hair is all about repairing the cuticle and helping it hold onto moisture better. Deep conditioners, nourishing shampoos, and certain plant oils can all help. Using your fingers to gently detangle hair, avoiding heat and chemicals, and patting hair dry with a microfibre towel or t-shirt can reduce breakage and help your hair recover.
In general, high-porosity hair is less healthy than lower-porosity hair. Virgin hair (i.e. hair that’s untouched by chemical treatments or colour) is often less porous than treated hair. Hair tends to become more porous with increasing exposure to chemicals, sunlight, heat treatments, and other damaging factors.
High porosity hair continues to grow, but you may not see any changes in length. This is because highly porous hair is brittle and prone to breakage, so you may be shedding hair at the ends of your strands at the same rate as it’s growing from the roots.
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