One of the more confusing aspects of hair types is porosity. It’s important to understand what hair porosity type you have so you know which products to use for healthy hair.
Porosity has a massive effect on how your hair behaves. Does your hair frizz easily? Perhaps your hair often breaks when you brush it? Ever see your hair get weighed down by a moisturizer? Hair porosity type has a direct correlation to how your hair reacts to weather and hair care products.
A big step to better looking hair is understanding the concept of porosity and identifying your own specific hair porosity type.
What is Hair Porosity?
Porosity is your hair’s ability to absorb and retain moisture. There are three levels of porosity: low, medium, and high. The optimal porosity type is medium porosity, because it allows the best balance of moisture absorption and retention.
Your genetics may give you a predisposition for high porosity, but chemical processing, harsh weather, and excessive heat styling can also cause hair damage and high porosity.
Porosity is controlled by the hair cuticle, which is the outer layer of the hair strand. The cuticle is made up of microscopic overlapping scales. When the cuticle is healthy, the scales lay flat, retaining moisture, making the hair look luxurious. High porosity hair has cuticle scales that are in an open position, meaning moisture flows in, causing frizz, and flows out, creating dry brittle hair.
Hair Structure and Porosity
To fully understand porosity, you need to understand the structural composition of each hair strand. Your hair is made up of three distinct layers: the cuticle, cortex, and medulla.
Cuticle
The hair cuticle is the outer protective layer of the hair. This is a thin layer made of overlapping scales. When the cuticle scales are laid flat, moisture is kept sealed in the hair strand. If the cuticle scales are lifted open from damage, moisture can flow in and out of the hair, meaning porosity is high.
Cortex
The cortex is the middle layer of the hair, making up most of the mass of each strand. Located right below the cuticle, the cortex gives your hair its strength, color, width, and other notable characteristics.
When your hair cuticles are open and porous, the cortex can sustain damage. When the cuticle is laying flat, and porosity is lower, the cortex stays healthy and hydrated.
Medulla
The medulla is the innermost part of the hair strand, usually only found in thicker hair types. It is made up of thin, soft transparent cells and air spaces.
Hair Porosity Types
Hair porosity is divided into three general categories.
Low Porosity
Hair with low porosity features cuticle scales that lay flat and smooth, trapping moisture inside. This also means moisture is less likely to penetrate hair cuticles, making hydration more difficult.
Medium Porosity
If your hair has medium porosity, the scales are looser, but moisture is absorbed and retained. Medium porosity hair is the easiest porosity type to maintain. Hair with medium porosity takes chemical treatments like coloring, relaxing, and bleaching well with fairly predictable results, This type of hair tends to look healthy, glossy, and voluminous.
High Porosity
Hair with high porosity has cuticle scales which are in the “open” position. This means moisture flows in and out of the hair shaft continually, making hydration difficult. Humid weather can cause high porosity hair to frizz. High porosity can also cause hair to be dry and brittle. High-porosity hair requires lots of moisturizing. Coloring treatments tend to fade quickly with high porosity hair.
What Causes Low or High Hair Porosity?
Genetics plays a big role in whether you have low, high, or normal porosity hair. This is not the only factor, however. Overwashing, chemical processing, coloring, bleaching, perming, blow drying, ultraviolet rays from the sun, heat styling, aggressive brushing, and exposure to harsh weather can all cause your hair porosity to increase.
Is There a Way to Test Your Hair Porosity?
There are a few ways you can test the porosity of your hair. Remember to test your hair after you have washed your hair, and it is free of product build-up. For example, if you just used a hair mask that can affect the accuracy of the test.
The Float Test
Take a strand of hair and place it in a glass of room temperature water.
· If the hair sinks quickly, it has high porosity.
· Hair that sinks at a moderate pace, it has medium porosity.
· If the hair floats, it has low porosity.
The Spray Test
For this test, take a strand of your hair and spray water on it. What happens next will identify your hair’s porosity level.
- If droplets of water form on the hair, and they don’t absorb, you have low porosity hair.
- When the water forms small droplets of water which later absorb into the hair, your have medium porosity hair.
- If the water is absorbed almost instantly into the strand, you have high porosity hair.
How to Take Care of Porous Hair
Hair porosity doesn’t always get the attention required for healthy looking hair. There are specific hair care strategies for each type of hair porosity.
For Low Porosity Hair
Low porosity hair retains moisture well, but also doesn’t absorb moisture very easily. The hair product often “just lays” on the hair, leaving it dry. Because of this, deep conditioners are necessary to penetrate the cuticle and hydrate the cortex, which is the inner layer of the hair.
Using a low-sulfate shampoo occasionally will also help remove build-up of product which isn’t absorbed into the hair. This can help open up the cuticle and allow moisture to be absorbed more effectively.
Hair products which are lightweight, yet contain extra moisturizing ingredients, are the best choices for people with low porosity hair.
For Medium Porosity Hair
Medium porosity hair retains and absorbs moisture at optimal rates, meaning it stays healthy and hydrated. Use a gentle cleansing shampoo to remove product build-up, and nourishing conditioners which add moisturizing lipids to your hair.
Fortunately, medium porosity hair handles everyday conditions quite well. Excessive coloring and chemical processing may increase the porosity temporarily.
For High Porosity Hair
High porosity hair has large openings in the cuticle layer, so moisture passes in and out of the of the hair quite easily. This makes the hair susceptible to frizz in humid weather and dryness in dry weather. High porosity hair cannot retain moisture easily so it can be damaged quickly by UV rays, chemical processes, and heat styling.
Because high porosity hair needs lots of moisture and extra nourishment, using products with lots of protein and keratin will help repair the hair. Using hair masks and moisturizing shampoos and conditioners will help keep high porosity hair manageable.
Products containing anti-humectants will help seal the hair cuticle and keep hair from absorbing humidity from the air, which leads to fizziness. Leave-in moisturizing products with ingredients like avocado oil will help keep the hair hydrated.
Become a Licensed Cosmetologist in About 36 Weeks
If you’re looking for high-level training to become a professional cosmetologist, Paul Mitchell the School at Campus Sacramento has a 36-week cosmetology program. Students learn a proven program of hair styling, hair coloring, skin care, nail care, and haircutting. Graduates are ready for their licensing exam with the California Board of Barbering and Cosmetology. For more information, contact our Admissions team or call 888-675-2460.