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 assess when a new client sits in my chair, because it changes almost every recommendation I make after that.
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.
- 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 escapes just as easily, leaving hair chronically dry.
- Normal porosity sits in between, absorbing and retaining moisture at a relatively balanced rate.
Porosity can be largely genetic, but it's also influenced by damage, heat styling, chemical processing, and environmental exposure 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 clean strand of hair into a glass of water and see what it does. Hair that floats near the top for a while is generally considered lower porosity, since the sealed cuticle is resisting water absorption. 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. 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, which brings me to the next section.
Behavioral Signs of Low Porosity
- Products tend to sit on top of your hair rather than absorbing, sometimes leaving 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 helping moisture get past that tightly sealed cuticle in the first place.
- Apply products to damp, not soaking wet or fully dry, hair, 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 sealing 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, because they all inform each other. I can't give you an accurate, useful product recommendation without understanding how your specific hair is behaving, not just what texture or curl pattern it has. That's the difference between a generic routine and one that's actually 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. Check out our services page for the detox and consultation options I offer, or book an appointment and let's figure out what your hair actually needs to thrive.
