How to Know If You Have Low-Porosity Hair (and the 12 Products That Can Help)

Hair is a complicated topic. It seems like after decades of categorizing hair as simply curly, coily, or straight, there are suddenly endless categories and subcategories measuring everything from thickness to ultra-specific growth patterns. Perhaps the most elusive of all these typing mechanisms is hair porosity. Specifically, low porosity is such a mystery.

If you've heard this term before but aren't quite sure what it means, you aren't alone! Discussions of hair porosity, in general, have become more prevalent in the curly and natural hair communities, so if you aren't regularly scouting out information in that pocket of the haircare conversation, there's a good chance you just haven't come across this term. Trust us—this is information everyone can use! Ahead, we've put together a crash course on all things low-porosity hair, including the best products to care for it. Keep scrolling for the expert intel.

First of All, What Is Hair Porosity?

"Hair porosity determines your hair’s ability to absorb and retain moisture, as well as how oils pass in and out of the hair's cuticle," explains hairstylist and color expert, Sharon Spellman. "Essentially, the higher the porosity is, the more exposed your hair becomes." Celebrity hairstylist Christin Brown agrees, adding that porosity also has a lot to do with how well moisture is able to enter and remain inside the hair shaft. As for the levels of hair porosity, there are three that are widely acknowledged: low, normal, and high porosity. "In a nutshell, hair porosity is the hair's ability to retain and accept moisture. Most folks in the natural hair community find this information useful when it comes to selecting the right products to help with benefits toward the hair's state," she says. Though talk of hair porosity is most common in the naturally curly and coily hair communities, Spellman says that everyone's hair, independent of hair type or curl pattern, can fall anywhere on the hair porosity spectrum.

So, What Is Low-Porosity Hair?

Low-porosity hair, or hair that is the least porous compared to normal and high porosity hair types, has strong bonds that are tightly closed and lay flat. "Low-porosity hair doesn't absorb or retain moisture well at all. When your cuticle is tightly packed together it creates no space between the cuticles, which makes it difficult to retain all that your hair requires," says Spellman.

Though the inability to accept and retain moisture sounds like a bad thing, low porosity isn't necessarily a bath thing. According to Brown, low porosity is often a sign of having extremely healthy hair or hair that hasn't been compromised by chemical treatments that could have broken down the hair bonds. On the other hand, low porosity can also be the result of intense product buildup that's acting as a kind of temporary shield between the hair and outside elements—even beneficial ones. "Your hair isn't able to accept additional hydration and can be more prone to dryness. This isn't true for all people, but for those who are experiencing these situations, it can be frustrating. For folks who have low-porosity hair, I actually bend the rules and tell them to cleanse their hair in hot water to help open up the hair cuticle which can be extremely helpful," Brown told us.

Spellman points out that due to its closed bonds that aren't as receptive to penetration from the outside, low-porosity hair can be challenging when it comes to drying it, coaxing it into retaining moisture, and even taking chemical processing like color. But, again, there are some major benefits as well. "On the flip side, people with low-porosity hair typically have glossier, less frizzy hair," she says. Similarly, Brown points out that, with proper care, low-porosity hair can generally hold color for much longer than hair with varying levels of porosity.

How to Tell If You Have Low-Porosity Hair

As mentioned above, there are some tell-tale signs that can help you determine whether or not you have low-porosity hair. For starters, Brown says to pay attention to how long it takes for your hair to become fully wet in the shower and how long it stays damp when products are applied. "When someone has low porosity, their hair may take longer to get wet in the shower, may repel water, and also not accept products easily," she explains. More signs of low porosity are intense product buildup resulting from products sitting on the surface instead of sinking in and excessive dry times after washing.

There's another, more empirical way to tell if you have low-porosity hair, though. It's actually a test you conduct at home in just a few minutes. "All you need is a clean glass of water and a strand of hair. Place one strand of your hair into the water and watch if it sinks or floats. If your hair floats, it's low porosity. If the strand floats then begins to sink slowly, that's considered normal porosity. Lastly, if your hair sinks immediately, it's high porosity," says Spellman. This test can yield accurate results, but Brown warns to make sure you're testing a clean strand of hair. "Sometimes it has more to do with whether your hair has product buildup when the test is performed, which can give you a skewed result," she clarifies.

Expert-Approved Product Swaps for Low-Porosity Hair

Instead of Protein Treatments…

Try Deep Conditioning Tools

Instead of Thick Creams…

Try Penetrative Moisturizers

Instead of Cream Cleansers…

Try Clarifying Shampoos

Instead of Heavy Oils…

Try Water-Based Stylers and Lightweight Oils