What Is Hair Porosity and How Should It Change Your Routine?

Hair porosity is how open your cuticle is, and it decides whether a product soaks in or sits on top. Low porosity does not mean healthy hair. High porosity does not mean ruined hair. At Bokaos in Old Town Pasadena, we read porosity at the shampoo bowl before we recommend a single product. On long hair, we read it zone by zone.

One complaint we hear at the bowl over and over: a conditioner works on a friend and leaves your hair limp and coated. Same bottle, different hair. Porosity also explains color that fades fast, a leave-in that disappears by noon, and a mask that sits on your hair like a film. Once you know yours, you can stop guessing in the product aisle.

What is hair porosity, and why does it change which products work?

Hair porosity is how open the cuticle is. The cuticle is the outer layer of each strand, and it decides how easily water and product get in and out. Low porosity hair needs light products in small amounts. High porosity hair needs richer conditioner, leave-in, and heat protection. Use the wrong product for your type and it either sits on top or rinses straight out.

Think of the cuticle as roof shingles laid over each strand. When the shingles lie flat, water has a hard time getting under them. When they lift or chip, everything gets in fast. Then it all gets out again just as fast.

Two things set your porosity. Genetics gives you a starting point: some people are born with a tight cuticle and some with a more open one. Then life adds to it. Lightening, repeated color and other chemical services, heat tools, and rough brushing on wet hair all lift the cuticle over time.

Length matters too. The ends are the oldest hair on your head. They have been through every blow-dry, every color appointment, and every towel rub since they grew in. Your roots have been through almost none of it.

So one head often has more than one porosity. We see that most on long hair, which is a big part of what we do here.

Porosity is not a grade. It describes how your hair behaves, nothing more. A high porosity head can be natural and healthy. Low porosity hair can be coated with buildup and miserable. If you also want density and curl pattern explained, our stylist's guide to porosity, density, and curls covers that side.

How can you tell if your hair is low, medium, or high porosity?

Your hair tells you through how it wets, how it dries, and how it takes product. Each type has its own signs and its own needs.

Low porosity

The cuticle sits flat and tight. Water beads on dry hair for a moment before it soaks in. In the shower, hair takes a while to get fully wet. After, it takes a long time to air dry. Creams and oils tend to sit on the surface and leave a greasy film. The hair often looks shiny, and color or treatments can be slower to take.

What helps is lightweight products in small amounts and warm water at the shampoo. A clarifying or chelating shampoo helps when hair starts to feel coated. What hurts is layering. Heavy butters, thick oils, and three products stacked on one another just build a wall.

Medium porosity

The cuticle is slightly open. Hair holds a style, takes color in a predictable way, dries in a sensible amount of time, and tolerates most products. This is the easiest type to live with.

Upkeep is about protecting what you have. Use heat protectant before every tool, keep up regular trims, and think twice before stacking chemical services close together.

High porosity

The cuticle is lifted or has gaps. Hair soaks up water at once and dries fast. It frizzes, tangles, and looks dull. Products seem to vanish within hours. Color and toner fade quickly because the strand cannot hold pigment.

There are two causes. Some people are born with it. Others earn it through lightening, repeated color, and heat. Either way, the hair needs richer conditioner, a leave-in before heat, cooler rinse water, and fewer back-to-back lightening services. After chemical work, a bond builder can help. We carry Olaplex for that.

Mixed porosity

Mixed porosity means the roots sit on one setting and the ends on another. The roots read low or medium, and the ends read high. It is the type we plan around most.

Treat the head in zones. Use lighter product at the roots and richer product on the midlengths and ends. One product slathered from scalp to tip is how roots go greasy while ends stay dry.

How does porosity change color, blonde, and smoothing services?

Porosity decides how color behaves, so we feel your hair before we mix anything. A strand that holds pigment well and a strand that drops it in days need different plans.

High porosity hair takes pigment fast and lets go of it fast. That is why toner on lightened hair can look perfect at the chair. It can also fade sooner than you expected. It is a big reason the pieces around your face often turn warm before the rest. We break that down in why your face-framing pieces go brassy before the rest of your color.

Lightening raises porosity by itself. Each lift opens the cuticle a little more. So if your blonde is already porous, the answer to "can we go lighter?" is sometimes "not today."

We would rather tell you that than stack lift on a strand that cannot take it. A gloss can refresh the tone. A plan that spreads the change over two appointments also protects the hair you came in with.

Low porosity hair can go the other way. Color may be slower to take, and that can mean more time in the chair. A slow start is normal for a tight cuticle.

Porosity is one piece of how we decide how much hair needs foils. The rest of that conversation is in half head foil vs. full head of foils.

Smoothing services like a keratin treatment or a Brazilian Blowout start with the same check. The condition of the strand tells us whether to go ahead, wait, or do something gentler first.

Does Pasadena's hard water change how your hair behaves?

Pasadena's water does not change your porosity, but it can hide it. Pasadena tap water is hard. Minerals from it settle on the strand with every wash.

On low porosity hair, that film stacks onto a cuticle already holding things out. Hair feels heavy, stiff, and coated, and conditioner seems to do nothing. On high porosity hair, the same minerals leave color dull and warm, and ends feel rough.

Buildup can also make a porosity test lie. A coated strand can read as low porosity when the strand underneath is far more open. If your results feel odd, use a chelating shampoo first and test again. We walk through the whole routine in how stylists care for hair in Pasadena's hard water.

How do you check your own porosity at home?

You can get a rough read in one wash cycle. Do this once and write down what you find.

1. Wash with a plain shampoo. Skip conditioner and styling product.
2. Let your hair air dry completely, with no heat.
3. Pinch a single strand near your ends and slide two fingers up toward the root.
4. Notice whether it feels smooth, slightly rough, or bumpy. Done right, you can feel a difference between ends and crown.
5. Repeat at the midlengths and at the crown.
6. Write down what you found in each zone before you buy anything.

Smooth means a tight cuticle. Bumpy or rough means lifted. Next, mist a dry section with water and watch. If the water beads, think low porosity. If it soaks in at once, think high.

You may have heard of the float test, where you drop a clean strand into a glass of water. We treat it as a hint, not a verdict. Oils, product, and buildup change whether a strand floats, and one strand cannot speak for a whole head.

A stylist reading your hair at the shampoo bowl and under the light is a better test than any glass of water.

What should your routine look like for each type?

Match the routine to your porosity and most other product choices get easier. Low and high porosity need the most different routines. Medium porosity mostly needs the upkeep covered above.

A routine for low porosity hair

1. Shampoo with warm water so the cuticle relaxes a little.
2. Apply a lightweight conditioner from midlengths to ends, and keep it off the roots.
3. Add gentle heat for deep conditioning, like a warm towel. Leave it on for the time the label gives.
4. Finish with a few drops of light leave-in on damp hair.

When your hair starts to feel coated, use a clarifying or chelating shampoo. Ask us how often that should be for your head. It depends on your water, your products, and how much you style.

A routine for high porosity hair

1. Shampoo the scalp only and let the suds rinse down through the lengths.
2. Condition from midlengths to ends at every wash.
3. Rinse with cool water to help the cuticle lie flatter.
4. Apply leave-in to damp hair before you touch any heat.
5. Use heat protectant before every tool, every time.
6. Dry by pressing with a soft towel, not rubbing, and detangle from the ends up.

On top of that, schedule a deep conditioning treatment or a bond builder. Fit it to how much color and heat your hair sees. For dry, thirsty hair, our owner has a deep conditioner she reaches for. We explain why in our post on Lakme Teknia Deep Care Conditioner.

As an Aveda concept salon, we also build routines around Aveda's plant-based, cruelty-free products. Kérastase, Color WOW, and Olaplex are on our shelves too.

What do people get wrong about porosity?

Most mistakes come from treating one label as a whole diagnosis. Each one costs you product, time, or the color you paid for.

• Thinking low porosity means healthy and high porosity means ruined. Both are only a description.
• Adding more product when hair feels dry. If your hair is low porosity, the product is sitting on top and more of it makes things worse.
• Trusting the float test alone.
• Treating every length of hair the same, when the ends and roots have different histories.
• Skipping heat protectant because the hair is already damaged. Hair that is already porous needs more protection, not less.
• Expecting a deep conditioner to close the cuticle for good. Conditioner smooths the surface for a while. Damage in the ends stays until it grows out or is cut off.

What if you are worried about the state of your hair before you book?

You can book with us whatever shape your hair is in, because we check your porosity and your history first. The worry we hear has two parts. Will color wreck my hair? Will someone judge the shape it is in?

The answer to the first depends on your porosity and your history. We check both before anything touches your hair. The answer to the second is no. We have been working in Old Town Pasadena since 1991. We have seen every version of box color, heat damage, and overdue trims.

This is from a Google review left by one of our clients: "It was my first time coloring my virgin hair, and Has and her amazing assistants made the whole experience so comfortable. They explained everything, took great care of my hair, and the results came out even better than I expected."

Has is our owner, Hasblady Guzman. That is the standard we hold the whole team to: you hear the plan before the color goes on.

Here is what the consultation looks like. We run our hands through your hair, section by section. We ask what has been on it: box color, past lightening, a keratin treatment, how often you use heat. We compare your ends to your roots.

Then we tell you what can happen in one appointment and what needs two, and why. If the right call is to wait, or to skip a service, we say so.

Consultations are required for extensions and highly recommended for big color corrections. If you are planning either, book your consultation and we will walk through the plan before we start.

Frequently Asked Questions

What is hair porosity?

Hair porosity is how easily your hair absorbs and releases water and product, based on how open the cuticle is. Low porosity hair resists moisture. Medium porosity hair takes it in and holds it. High porosity hair takes it in and loses it quickly, and most people have a mix across their head.

How do I know if my hair is low or high porosity?

Watch how it behaves after a plain wash with no product. Low porosity hair wets slowly, dries slowly, and lets product sit on top. High porosity hair soaks up water fast, dries fast, and frizzes easily. A dry strand that feels smooth points to low porosity, and a rough one points to high.

Does the float test for porosity work?

No, not on its own. It gives a hint, but we would not make decisions from it. Feeling the hair in zones, and seeing how it takes water and product, tells us more.

Can you change your hair's porosity?

No, not for good, but you can change how it behaves day to day. Conditioners, leave-ins, and bond builders smooth and support the strand for a while. Damage in the ends stays until that hair is cut off or grows out. The change that lasts is protecting your hair from more heat and lightening.

Is high porosity hair always damaged?

No. Some people are born with a more open cuticle and have healthy hair with high porosity. Damage from color, lightening, and heat is the more common cause on lengths and ends, though. We look at where on the strand the porosity shows up to tell the two apart.

How does porosity affect hair color?

It changes how fast color goes in and how long it stays. High porosity hair can let toner fade sooner, while low porosity hair can be slower to take color. We check porosity before we mix so the plan fits the strand in front of us.

Does Pasadena's hard water affect porosity?

No. It does not change your porosity, but it can mask it. Low porosity hair ends up feeling heavy and coated, and high porosity hair looks dull. A chelating shampoo helps clear it, and we can tell you how often to use one.

Should I come in for a consultation before coloring porous hair?

Yes, especially for a big color change. We check porosity and hair history first, then tell you what is possible in one appointment and what takes two. Pricing depends on your hair and the stylist you book, and current pricing is on our service menu.

Book a Consultation

If your hair soaks up water like a sponge or sheds it like a raincoat, bring that to us. Come in for a consultation at Bokaos, 52 Hugus Alley in Old Town Pasadena. We will look at your hair and tell you what is possible. Book your appointment online or call us at (626) 304-0007.