Photo of a woman with low porosity hair, curly hair, natural hair, kinky hair

So... What's This Whole Thing About Porosity?

**For brevity and concision, all Science of Hair topics are 550 words or less**

What is Porosity?

In chemistry, porosity refers to the ratio between the amount of void spaces in an object with the overall mass of the object. The more porous an object is, the less it retains fluids. In simple terms: Porous things have a lot of holes in them. An example of a non porous object would be a rock. An example of a very porous object would be a sponge. 


What does this have to do with my hair?


Hair porosity refers to your hairs ability to retain water and moisture due to the tightness of hair cuticles. Depicted above is a healthy straight hair strand with normal porosity. The cuticle layer is well compacted enough to prevent unwanted debris from entering the shaft, but flexible enough to swell* and allow moisture penetration.  

Terms to Know  

Cuticles: Dead and compacted skin cells that make the outer layer of your hair (the average strand contains 6-10 layers of cuticles comprised of a keratin and protein mix) 

Medulla: Fragile and thin inner layer of the hair, commonly called the "marrow" of the strand. 

Cortex: The thickest hair layer. Holds pigment and gives hair its color.

Swell: The "lifting" process of cuticles when interacting with water/moisture products to allow product penetration.  


Low Porosity Hair 

When the cuticles on the hair strand are tightly compacted, moisture applied to the hair does not penetrate the shaft, but instead “sits” on top of the strands exterior. This is commonly known as low porosity hair. 

Common Characteristics of low porosity hair 

  •  Hair air dries slowly

  • Hair is prone to build-up

  • Hair takes time to get fault drenched  

  • Products do not feel fully penetrating


Low Porosity Moisturizing Tips 

  • Try shampooing hair weekly to get rid of product build-up 

  • Use heat when deep conditioning for maximum penetration

  • Use Humectant based (moisture attracting) products

  • Water is one of the best moisturizers for your hair. Use it frequently! 

  • AVOID protein treatments if your hair does not react well. 


Low porosity Styling Tips 

  • If needed, prime styles with light oils.  

  • Use satin scarves and pillowcases to reduce sleep friction and split ends 

  • Avoid heavy creams that tend to “sit” on the strand 


Click here to find Low Porosity friendly products!


High Porosity Hair

The opposite is true for high porosity hair. Due to hair cuticles being loosely compacted, moisture applied for penetration purposes quicky escapes the hair shaft. 


Common Characteristics of High Porosity Hair

  • Hair air dries quickly 

  • Dry hair tangles and matts easily 

  • Ends of hair look frayed  
  • Hair is hyper prone to breakage 

  • Hair has trouble retaining moisture 


Common Causes of High Porosity Hair 

  • Hydral fatigue (damage caused by repeated swelling and un swelling of hair follicles in response to hyper saturation)  

  • Excessive hair processing (beaching, dying, or chemically altering the hair) 

  • Genetic predisposition 

  • Consistent use of high heat tools (causes cuticles to raise) 


High Porosity Moisturizing Tips 

  • Try shampooing bi-weekly (consistent shampoo can lead to exasperating dryness) 

  • Utilize protein treatment every 2-3 weeks 

  • Use products with heavy humectant (moisture grabbing) ingredients [think aloe vera]

  • Seal moisture with emollient (moisture trapping) based products such as [ think butters]


High Porosity Styling Tips 

  • Prime styles with a liquid based product, and seal with a light creamer one 

  • Avoid excessive heat and processing (further damages cuticles) 

  • Avoid hot water when shampooing to mitigate dryness 

  • Avoid overuse of hard bristle brushes that slowly fray cuticles


Click here to find High Porosity friendly products!


Don't know your hair's porosity? Take the 5 step porosity test! 

 5 Step Porosity Test 

  1. Fill a glass of water with PH 7 water (or water from your tap) 

  2. Pluck a clean strand of hair

  3. Place hair in glass 

  4. Wait 1 minute 

  5. See where it 

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1 comment

So informative!! Thank you guys for putting the work into this research!

Macy Berryman

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