Beauty All Natural What Is Hair Porosity and Why Is It So Important? Plus, how to care for all levels of porosity. By Erin Lukas Erin Lukas Instagram Twitter Erin is a Brooklyn-based beauty editor and has been with InStyle since 2016. She covers all facets of beauty for the site. InStyle's editorial guidelines Updated on January 5, 2023 @ 09:42AM Pin Share Tweet Email Photo: Getty Images You've figured out your hair texture, scoured product reviews on social media, curated a product lineup in your shower, and used said products on your next wash day. The only problem? Your curls still aren't as soft and shiny as you'd like. While identifying your hair type and building a solid haircare routine around it is important, it's only half the equation to a good hair day. Your hair's porosity is also a factor when it comes to determining the best products for your hair needs. Maybe you've seen hair porosity being mentioned on social media and it's left you stumped. To put it simply, your hair porosity is your hair's ability to absorb and retain moisture. So, how do you determine your hair's porosity level and why does it matter so much? We tapped Vernon François, a celebrity hairstylist, educator, and founder of Vernon François Haircare, and Isfahan Chambers-Harris, a trichologist, Ph.D. Scientist, and founder of Alodia Hair Care, to help us break down everything you need to know about your porosity. Your Complete Guide to Discovering Your Natural Hair Type Why is understanding your hair porosity so important? "Understanding your hair's porosity is important because it means you will get to know your hair better," François says. "The better you know your hair, the more confident and successful a relationship you will have with it." While your hair texture (kinky, coily, curly, wavy, or straight) will determine what tools you use and your lifestyle, like how often you wash your hair, your porosity will influence which products you use and how you use them (amount, frequency, and order). With that in mind, François points out there are no hard and fast rules regarding what hairstyles are best for different porosity levels, and in the end, it's always best to do what works best for your hair. "Many other factors come into play," he adds. "The key is exploring what works best for you as an individual and your unique head of hair." All 4 Hair Types & How to Style Them, According to Celebrity Stylists What are the levels of porosity and how do I know which one I have? First things first: there are three levels of porosity (low, medium, and high). "The outside layer of the hair's shaft is called the cuticle, which, at a microscopic level, overlaps like how tiles or scales do," François explains. "However much this lifts or not determines how porous your hair is." Getty Images Low porosity hair: Low porosity hair where the cuticle lays very flat. "Running water over this hair, you may notice that the water flows over and off it easily, before starting to be absorbed by strands," François says. "Low porosity hair is not necessarily difficult hair or problem hair. It's hair that is easily kept in a healthy condition and is strong and elastic," says Dr. Chambers-Harris. "If your low porosity hair feels dry, wiry, tangly, or brittle, it doesn't mean that it is damaged it is just lacking hydration, softness, and flexibility." Medium porosity hair: François says medium porosity hair is in the middle of high and low porosity, and it absorbs and loses moisture steadily. High porosity hair: Finally, high porosity hair has a lifted cuticle layer. And while this means it can absorb water, product, and oil easily, it can readily lose moisture, too. Exposure to chemical treatments and UV rays can lead to a higher porosity level. "According to the National Center for Biotechnology Information (NCBI), hair that's extremely porous are hair strands that are damaged by things such as UV exposure, hair bleaching, chemical relaxers, or intense heat over long periods, " says Dr. Chambers-Harris. "Exposure to these things leads to an increase in porosity levels, causing your hair to have high porosity." How to care for your porosity level: "Low porosity hair may benefit from steam treatments or covering the hair while conditioning to encourage the cuticle layer to lift open and let [the] goodness in," François suggests. "Strands may respond to lighter formulas, and rinsing hair with cold water after conditioning may encourage the cuticle to lay flat again." High porosity hair typically requires more oil or protein to help restore and moisture. "Some conditioners have more protein in them, so look for conditioners with keratin, wheat, or silk protein for added strength," says Dr. Chambers-Harris. The Deep Conditioning Masque from her line, Alodia, contains both oils and wheat protein. François suggests high porous hair try a hair cream, like the Styling Cream from his line because it "smooths the cuticle layer at the same time as absorbing into the deeper part of strands." Following up with a serum, like Kérastase's Curl Manifesto Huile Sublime Repair, can also help seal in moisture. And finally, using a shampoo and conditioner designed to repair, while being gentle on stressed or damaged hair is also a good idea. François is a fan of Redken's Acid Bonding Concentrate collection, which helps strengthen hair from the inside out, and instantly boosts softness and shine. This is All Natural. From the kinkiest coils to loose waves, we're celebrating natural hair in its many forms by sharing expert tips for styling, maintenance, and haircare.