My sister once asked me to recommend a product for her low-porosity hair, and honestly, I was stumped. I had heard a few of my friends mention their hair's porosity in conversation. I even went as far as to test my strands at work with a few of my curl friends. After testing my curls, I didn't adjust my hair routine or run out and purchase new products because I still didn't quite understand why knowing my hair's porosity was important. After some research and a chat with two hair experts, I understand getting to know your hair porosity can tell you if your curls are damaged, in need of moisture, or if they're healthy.
To take an expert crash course in porosity, I reached out to Dr. Isfahan Chambers-Harris, medical scientist, hair trichologist, and founder of Alodia Hair Care, as well as Robin Groover, the owner of Atlanta-based Too Groovy Salon.
Meet the Expert
What Is Hair Porosity?
Essentially, porosity determines how your hair can retain and absorb moisture. "Porosity can be broken down into three categories: low, normal, and high," says Groover. "Low porosity hair has cuticles that are bound very close together, normal porosity hair has cuticles that are slightly less bound, and high porosity hair has cuticles that are more widely spread out."
How to Test Your Hair Porosity at Home
There is a simple way you can test your hair's porosity at home. You just need two things: a glass of water (use a clear glass) and a strand of hair. It is recommended that you try this after washing the product and build-up from your strands to get the most accurate reading. "Start by combing your hair to release strands that are shedding, and then take those stands and drop them into your glass of water," says Groover. "Hair that is low porosity will float. Hair that is 'normal' porosity will float and then begin to sink slowly. Hair that is high porosity will sink immediately."
Low Porosity Hair
If you have low porosity hair, Chambers-Harris says that it means your hair is technically in a healthy state, which goes against the common myth that low porosity hair is unhealthy. "I love to tell people [it's a myth]," she shares. "Low porosity [hair] is actually healthy hair that is not being moisturized correctly. The cuticle layer is intact, but you're not moisturizing it properly, so it becomes dry and tangled."
Chambers-Harris likes to use a straw to explain low porosity hair. "If you have a straw and put holes in it, you can take in the liquid easily, but you can't retain the liquid. Once you take it out of the liquid, it's all going to run out of the straw." One of the easiest ways to ensure your hair is getting the moisture it craves is to wash and condition it once a week (twice a week tops). "When you're thirsty, you don't drink conditioner or oil—you drink water." Aside from washing your hair weekly, she shares a pro-tip that can help get your wash day off to a good start: "Use an oil that can actually penetrate your hair strands before you shampoo. If you look at ancient cultures, they always tended to oil their hair before [cleansing]."
She says pre-pooing can not only help moisturize the hair, but it can prevent nicks in your strands. "It's called hygral fatigue," she explains. "When you just jump in the shower, and you're putting warm water on your hair, your hair swells and will contract really quickly, which causes nicks to happen in your strands." Be sure to select a pre-poo oil that won't sit on top of the hair. Dr. Chambers-Harris recommends avocado oil. "It's an amazing emollient oil, and it actually will penetrate the hair strands, and it helps to moisturize it from within."
Hygral fatigue is a breakdown of the hair cuticle caused by excessive moisture entering and exiting. Hair that has experienced hygral fatigue may feel gummy or mushy when wet.
"Normal" Porosity Hair
Normal porosity hair is the easiest hair type to maintain because the hair cuticles tend to be looser, and because of that, moisture penetrates the hair with ease. If you're lucky enough to have medium porosity hair, Groover recommends a deep conditioning mask to maintain your hair health. "Incorporating deep conditioners in your regimen to maintain hair health and increase product absorption is key to achieving the best styling results," says Groover. She recommends a mask that balances and moisturizes like African Pride's Moisture Miracle Moroccan Clay & Shea Butter Masque. "The Moroccan clay works to balance the hair by removing impurities and product build-up, while the shea butter works to strengthen and replenish moisture."
High Porosity Hair
If your curls are experiencing excessive dryness, frizz, and snap easily, these may be a sign that you have high porosity hair, or hair that has a raised and porous cuticle. "With high porosity [hair], you can take in water, but you can't retain the water," explains Chambers-Harris. "Because the protein structure of your hair, the cuticle layer is damaged from coloring, relaxing, etc. and you can't hold onto it." Chambers-Harris says how you treat your hair can affect your hair's porosity. "Let's say you have dyed your hair, you have a relaxer, or you're out in the sun a lot, then [the hair] tends to be high porosity." She says that doing anything that is damaging the cuticle layer often—even coloring the hair once or getting too much sun or chlorine—could leave you with high porosity hair.
No matter the porosity of your hair, Chambers-Harris has four tips for all hair types. "Use an oil before you shampoo, use a non-sulfate shampoo, use a deep conditioner with equal amounts of protein and moisture to balance out your hair strands, and follow up with a water-based moisturizer."
She leaves us with one more word of advice: "You always have to remember your hair strands are dead. You really have to help to keep them from getting damaged." Keeping your routine consistent and simple is a great way to keep the hair moisturized and looking its best.
An overview on hair porosity. NYSCC.
Gavazzoni Dias MF. Hair cosmetics: an overview. Int J Trichology. 2015;7(1):2-15. doi:10.4103/0974-7753.153450
Hessefort Y, Holland BT, Cloud RW. True porosity measurement of hair: a new way to study hair damage mechanisms. J Cosmet Sci. 2008;59(4):303-315.