Hair porosity influences how well hair absorbs water, oils, and hair care products. Your hair porosity can range from low to high. High porosity hair absorbs water easily and air dries quickly. It can also respond rapidly to hair dyes and chemical treatments, causing unexpected results. High hair porosity can occur naturally in curly and coily hair or arise from damage to the hair cuticle.
High porosity hair is more likely to become damaged and dry, making this hair type sometimes challenging to care for. Hair care practices like layering products to seal in oils, using protein treatments, and limiting heat styling can help you care for high-porosity hair.
Your hair consists of a cuticle, cortex, and medulla, all of which help protect your hair from damage and retain moisture. The cuticle—the outermost protective barrier of your hair—can be easily damaged by chemical treatments such as perms, bleach, chemical straighteners, and color treatments.
Heat styling and exposure to ultraviolet (UV) light can also damage the cuticle. Once this occurs, your hair’s cortex and medulla are at risk for damage, too. Damage to the hair shaft can create spaces or voids in the shaft, increasing your hair’s porosity.
High porosity hair typically contains several voids or spaces in the cuticle. Sometimes this occurs when your hair is damaged through treatments and grooming practices. Other times, it is a natural characteristic of your hair’s structure.
Who Is More Likely To Have High Porosity Hair?
You may be more likely to have high porosity hair if you use chemical processes on your hair, such as perming or bleaching, or if you often use heat to style your hair, such as using a blow dryer or curling iron.
High porosity hair is also common in people with textured hair, or hair that contains lots of curls and coils. This type of hair structure naturally tends to have lifted cuticles along the hair fiber. People with African ancestry tend to have high porosity hair.
Also, people with gray hair or light-colored hair and people of older age are more likely to have highly porous hair.
High porosity hair can have various characteristics. A defining trait of this hair type is that it absorbs water quickly, especially compared to low porosity hair. High porosity hair is also more common in people with curly or coily hair or hair damaged by chemical treatments.
Possible characteristics you may notice in high porosity hair include:
- Appears dry, frizzy, and brittle
- Absorbs water, hair products, and other liquids quickly
- Tends to dry quickly and feels dry to the touch
- Breaks easily when grooming or styling
- Loses moisture or hydration at a rapid rate
- Experiences accelerated and inconsistent results after chemical treatments
- Accepts hair colorants faster
- Appears cooler in color after treatments than less porous hair
- Looks dull and does not reflect light well
Knowing the porosity of your hair can inform you how best to care for it and why it responds to hair care products, hair drying, and treatments the way that it does. A few lab tests are available to test hair porosity, such as measuring hair fiber swelling in response to water and humidity. However, you can also test your hair’s porosity at home with a few simple methods.
Spray Test
To perform the spray test, use a spray bottle to spritz clean, dry hair with water. If the water droplets absorb into your hair right away and your hair becomes saturated quickly, your hair is high porosity. This happens because the cuticle is more open, allowing the water to enter the hair shaft faster. With low porosity, the water droplets may sit on the hair’s surface for a few seconds before soaking in.
Float Test
Another option for determining your hair’s porosity is using the float test. With this method, you will take a strand of clean, dry hair and drop it into a bowl of water. If the hair sinks quickly, it is high porosity. Low porosity hair will float, while medium porosity hair will sink slowly.
Slide Test
To use this method, pull a piece of clean, dry hair taut and slide your fingers upward along the hair shaft from the ends to your scalp. If your hair is high porosity, your fingers will move easily up the hair, but it may feel rough with bumps.
Low porosity hair will feel smooth, and your fingers will meet resistance trying to move up the taut strand. Medium porosity hair will have some resistance.
With high porosity hair, the hair’s cuticle is more open than that of low or normal porosity hair. This means high porosity hair will absorb products and chemical treatments more rapidly and is more prone to damage. To protect your hair and prevent further damage, you will need to take steps to treat your hair gently. Here are some ways to care for high porosity hair:
- Seal in moisture. If you have high porosity hair, your biggest challenge will be retaining moisture. Layering hair products can help seal in oils to maintain hydration. Try the LOC method: After shampooing and rinsing, apply a leave-in conditioner (L), followed by an oil (O), and finish with a creamy styling product (C).
- Select the appropriate oils. Researchers have found that polyunsaturated oils like avocado oil work well with high porosity hair. Another study found that using coconut oil and products with coconut oil can reduce the likelihood that your hair’s porosity increases.
- Use protein treatments. High porosity hair responds well to protein treatments, as these products help fill the voids in your hair’s damaged or lifted cuticles. You can also look for shampoos rich in amino acids (protein building blocks). However, avoid products with humectants, like glycerin and aloe vera, which do not always work well with high porosity hair.
- Talk to your stylist before treating your hair. High porosity hair responds rapidly and inconsistently to chemicals, such as those used in perms, hair dyes, and chemical straighteners. This means you can get more extreme colors and responses than someone with low porosity hair. Talk to your stylist about your hair porosity and how to use chemical processes safely. For instance, they can test a chemical on a small strand of your hair first to see how your hair responds and when to rinse out the treatment to avoid over-processing the hair.
- Protect your hair from further damage. Since the cuticle of high porosity hair is already open or damaged, it’s important to avoid further damage. Limit how often you treat your hair with colors or other chemicals, do less heat styling, and be gentle when grooming. Consider covering your hair when outdoors due to the risk of damage from pollutants and ultraviolet light.
- Avoid damaging ingredients in hair products. Overall, you should avoid hair care products that contain sulfates, parabens, sodium laureth sulfates, and silicones. These products can cause your hair to lose moisture and become dry, which is already an issue for high porosity hair.
Your hair’s porosity is determined by how well your hair absorbs water, treatments, and hair care products. If you have high porosity hair, your hair’s cuticles are lifted or have voids that allow them to absorb materials easily.
People with textured, curly, or gray hair and people with damaged hair are more likely to have high porosity. You can use a spray, float, or slide test to determine your hair’s porosity. Caring for high porosity hair involves layering oils and other products, using protein treatments, and avoiding certain ingredients like paragons, sulfates, and silicones.
