Hair Porosity Test: The 1-Minute Trick + 9 Hair Care Tips From Experts

Hair care, when you really dive into it, is complicated. See, hair has so many variables: To start, you have your hair type, which ranges from straight to kinks and coils. You also have your scalp type, which can range from oily to dry to irritated (sort of like your facial skin). Then you can have dense hair or sparse hair. You can have a thick strand diameter or you can have thin. 

To understand hair porosity, you should know a bit about the hair structure—specifically the outermost layer. "The outer layer of the hair strand is called the cuticle layer. It's called this because it is made of little tiny cuticles that lie slightly over one another," says hairstylist Danielle Malary of Lumiere Vive Salon. The most common analogy to use is like shingles on a roof: The shingles slightly overlap one another, so there are no gaps for water to seep through. Porosity comes in, maybe you've guessed by now because when something is porous, it is more able to absorb moisture. Thus hair that is "more porous" has more pores between the cuticles for water to get through. 

"Hair porosity describes how the hair's cuticle absorbs and holds on to moisture in its pores—hence, the term porosity," says hairstylist Miko Branch, co-founder of hair care brand Miss Jessie's. 

Now, hair porosity is a spectrum, ranging from high to low. It's good to know roughly where you fall on it, as it can determine how you care for and style your strands. We'll get into it more later, but as a briefer: Hair that has high porosity means the cuticles are more open, so hair absorbs water easily. But it also means it evaporates easily. Hair that has low porosity has dense cuticles. This means the hair has a harder time absorbing water, product, or even your scalp's natural oils, and you'll see buildup faster. It also takes longer to dry after getting wet as it's holding all that water in. Then you can fall somewhere between these two ends of the spectrum, which is considered medium porosity. 

So your strand sank. Now you know you have porous hair, in which water tends to flow more freely in and out. So hair absorbs water easily, as noted above, but it also means it evaporates easily. If this is you, here are a few qualities that might give it away: After a shower, your hair dries very quickly. It also becomes dry and brittle easily, needing moisturizing agents between washes. And when you do apply products, your hair will "drink" it up. Hair that has high porosity also tends to frizz easier and has a more matte appearance.

If you fall somewhere between these two ends, you're in luck: Your hair tends to be less high maintenance, as it doesn't swing to extremes on either end. Now you may have other things that concern you, like getting your curl pattern just right or adding volume, but as far as hydration and absorption are concerned, you're in the sweet spot.