Hair Porosity and What Your Curls Really Need

If your conditioner seems to sit on your curls one week, then your hair feels thirsty again the next, you don’t necessarily need a whole new shelf of products. Hair porosity may be part of what you’re seeing. It affects how readily your hair takes in water, conditioning ingredients and colour, and how easily it lets that moisture back out again.

After more than 40 years behind the chair in Australia and the UK, I’ve learned that curl problems rarely come down to one label. Porosity gives us a useful clue, but it works alongside curl pattern, density, strand thickness, damage, humidity and the way you treat your hair day to day. The aim isn’t to diagnose your hair like a science experiment. It’s to notice its behaviour, then give it what it responds to.

What hair porosity actually means

Each strand has an outer protective layer called the cuticle. Think of it as a series of tiny overlapping scales. When the cuticle lies fairly flat, ingredients can take longer to pass through it. When it’s more lifted or worn, water and conditioners can get in quickly, but may escape just as fast.

That’s the practical meaning of hair porosity. Low-porosity hair tends to resist water and product at first. High-porosity hair often wets quickly, dries quickly and can feel rough, puffy or dry even after conditioning. Medium porosity generally sits somewhere in the middle and is often easier to manage, although no head of hair behaves perfectly all the time.

Porosity can be genetic, especially where low porosity is concerned. It can also change. Bleaching, permanent colour, heat styling, harsh brushing, chemical services and plenty of sun and swimming can wear down the cuticle over time. Curly hair is often drier through the lengths anyway, because natural scalp oils don’t travel around bends and coils as easily. That’s why a curl can be naturally dry without automatically being highly porous.

Read your hair, not the glass test

You may have heard of the float test, where a strand of hair is dropped into a glass of water. I wouldn’t rely on it. Hair can have product build-up, oil or air on it, and one loose strand tells you very little about the rest of your head. It’s a bit like judging a whole roast by one pea.

Your regular wash day gives you better information. Notice how your hair behaves when it’s properly wet and freshly cleansed. Does water seem to bead up and take a while to soak in? Do conditioners feel as if they’re coating the hair rather than softening it? That can point towards lower porosity or build-up.

Or does your hair become wet immediately, tangle easily, feel rough when damp and dry faster than you expect? Is it constantly craving richer conditioning, particularly through coloured or lightened sections? Those are common signs of higher porosity.

Also pay attention to different areas. The hair near your scalp may be healthy and fairly resistant, while your ends are more porous from colouring and everyday wear. If you’ve got highlights, the lighter pieces may need a different level of care from the rest. One routine for the entire head is convenient, but convenience isn’t always the same as results.

When your hair is slower to absorb moisture

Low-porosity curls can look shiny and feel strong, yet still become dry, frizzy or weighed down. The issue is usually not that the hair needs no moisture. It’s that it can be harder to get moisture into the strand, especially if products are layered too heavily.

Start with a thorough cleanse when your curls feel coated, dull or strangely unresponsive. Build-up from styling products, oils and conditioners can make low-porosity hair feel as though nothing works. Then apply conditioner to very wet hair and give it a little time before rinsing. Warm water can help the hair feel more receptive, whereas piling on thick product after thick product often leaves curls limp.

Choose your texture carefully. Many low-porosity curl types do better with a lighter hydrating conditioner used consistently than with an ultra-rich mask every wash. My QUENCH Hydrating Conditioner is designed for hydration, while my AMPLIFY Volumising Conditioner can make more sense when fine curls are going flat under the weight of heavier conditioning.

Protein gets oversold in haircare conversations. Low-porosity hair isn’t automatically protein-sensitive, and protein isn’t automatically the enemy. But if your curls feel stiff, straw-like or less flexible after frequent strengthening treatments, reduce them and focus on hydration for a while. Your hair will usually tell you plainly enough.

When your hair takes in everything, then feels dry again

High-porosity hair often needs a different approach. It can absorb water and conditioner quickly, but because the cuticle is more open, it can lose moisture quickly too. This is why some curls feel soft in the shower and fluffy or rough by lunchtime.

Here, richer conditioning and regular treatments can be useful. My Repair Potion is a deep nourishing mask suited to dry, curly, damaged or coloured hair. Use it when the lengths feel depleted, not merely because Sunday has arrived. Haircare doesn’t need a diary appointment if your hair is having a good week.

Where there’s breakage, chemical damage or a loss of strength, my Anti Ageing Reconstructive Treatment is a strengthening option to work into the routine. The balance matters. Damaged, porous curls often need both moisture and strength, but too much of either can leave hair feeling wrong. If it becomes overly soft, stretchy and hard to hold a curl, it may need more support. If it feels rigid and dry, ease back on strengthening treatments and return to nourishing conditioning.

High porosity also benefits from kinder handling. Detangle with conditioner and patience, avoid rough towel drying, limit hot tools and use a heat protectant whenever heat is involved. If you colour your hair, a good colourist and sensible spacing between lightening services will do more for your ends than any single pot of treatment.

Build a routine around the result you want

Porosity is helpful because it explains why a product that your friend loves can leave your own curls greasy, brittle or still thirsty. But it shouldn’t become a box you can’t step out of. Your routine should change when your hair changes.

For most curly or frizz-prone hair, begin with a simple rhythm: cleanse when the scalp needs it, condition every wash, add a treatment when the hair feels dry or compromised, then style according to the finish you want. Fine curls may need lighter conditioning and less layering. Coarse curls often tolerate richer hydration. Coloured and heat-damaged hair may need more frequent care through the mid-lengths and ends.

How you apply products matters as much as what you buy. Conditioner spread over soaking-wet hair will behave differently from conditioner applied to hair that’s only damp. If your curls are dry, work water into them first. Water is the moisture. A conditioner helps manage, soften and hold onto it.

Give a change a few wash days before judging it, unless your hair immediately feels coated, brittle or irritated. Keep the rest of your routine steady while you test one thing at a time. Switching cleanser, conditioner, mask and styling products all at once makes it nearly impossible to know what helped.

Don’t blame porosity for everything

Frizz isn’t proof of high porosity. It can come from humidity, brushing dry curls, an unsuitable styling product, friction from bedding or simply a curl pattern that wants more moisture and hold. Dryness may also be caused by a harsh cleanser, hot water, frequent heat styling or not using enough conditioner.

Likewise, flat hair isn’t always low porosity. It may be fine, dense, over-conditioned or carrying too much product at the roots. If your scalp is oily but your ends are dry, treat those as two separate concerns. Cleanse the scalp properly and condition the lengths where they need it.

The useful question is never, “What category am I?” It’s, “What is my hair doing after I wash, condition and style it?” Watch that pattern for a couple of weeks. Your curls don’t need perfection or a complicated ten-step routine. They need you to notice when they feel balanced, then keep doing more of that.