If you've ever felt like you're doing everything "right" with your hair care routine and still not getting results, porosity is very often the missing piece. It's one of the first things I check when a new client sits in my chair, because it changes almost every recommendation I make after that. First check, biggest impact.
What Porosity Actually Means
Porosity refers to how easily your hair's cuticle, the outer protective layer of each strand, allows moisture in and lets it out. The cuticle is made up of overlapping layers, a bit like shingles on a roof, and how tightly or loosely those layers lay determines your porosity level. Cuticle position, nothing more.
- Low porosity hair has a tightly sealed cuticle. Moisture struggles to get in, but once it's in, it tends to stay.
- High porosity hair has a more raised, gapped cuticle. Moisture gets in easily. But it escapes just as easily, leaving hair chronically dry.
- Normal porosity sits in between. It absorbs and retains moisture at a relatively balanced rate.
Porosity can be largely genetic. It's also influenced by damage, heat styling, chemical processing, and environmental exposure, all of which can raise porosity over time by roughening the cuticle, even if your natural starting point was lower.
The Float Test (And Its Limits)
The most commonly cited at-home method is the float test: drop a strand of clean hair into a glass of water and watch what happens. It's that simple. Hair that floats near the top for a while is generally considered lower porosity, since the sealed cuticle is resisting water absorption, while hair that sinks quickly is generally considered higher porosity, absorbing water fast because the cuticle is more open.
I'll be honest with you the way I am with clients: this test is a helpful starting point, not a diagnosis, since product residue, water temperature, and even the oils naturally on your hands can all skew the result. A better read comes from paying attention to how your hair actually behaves day to day, not just what one test says. That's next.
Behavioral Signs of Low Porosity
- Products tend to sit on top of your hair rather than absorbing. Sometimes they leave a white, cast-like residue.
- Hair takes a long time to get fully wet in the shower and a long time to dry afterward.
- Buildup happens quickly, even with moderate product use.
- Steam or warm water noticeably improves how well products absorb.
Behavioral Signs of High Porosity
- Hair absorbs water and product almost instantly but dries out again quickly.
- Hair tends to feel rough or straw-like to the touch. Even after conditioning.
- Frizz and tangling happen easily, especially in humidity.
- Hair air-dries very fast, sometimes too fast, and often feels dry to the touch shortly after.
Caring for Low Porosity Hair
The goal here is simple. Help moisture get past that tightly sealed cuticle in the first place.
- Apply products to damp hair, not soaking wet and not fully dry, since this gives the cuticle its best chance to absorb.
- Use warmth to your advantage: a warm oil treatment, a heat cap, or even just applying products after a warm shower helps lift the cuticle slightly.
- Favor lighter, water-based leave-ins and avoid heavy butters or oils that will just sit on the surface and cause buildup.
- Clarify more regularly than you might think you need to, since buildup happens faster on low porosity hair.
Caring for High Porosity Hair
The goal here is simple. Seal moisture in before it has a chance to escape.
- Layer products using the LOC or LCO method: Liquid or Leave-in, followed by Oil, followed by Cream (or Cream before Oil, depending on which order your hair responds to better), to lock hydration in with heavier sealants.
- Use protein treatments more regularly to help temporarily smooth and strengthen the raised cuticle.
- Favor heavier butters and oils that create more of a seal than lighter, water-based products alone.
- Be extra diligent about heat protection and minimizing further cuticle damage, since high porosity is often partly the result of accumulated damage in the first place.
Why This Is Part of My Detox Service
When a client comes in for a Hair & Scalp Detox, part of what I'm doing during that appointment is genuinely assessing porosity, texture, and scalp condition together. They all inform each other. I can't give you an accurate, useful product recommendation without understanding how your specific hair actually behaves, not just what texture or curl pattern it has, and that's the difference between a generic routine and one built for your hair.
If your routine feels like it's fighting you no matter what you try, porosity is worth ruling in or out first. Start there. Check out our services page for the detox and consultation options I offer, or book an appointment, and let's sit down together and figure out exactly what your hair actually needs to thrive and how we'll get it there.
