Have you ever bought a product recommended by a friend, a colleague or an influencer, only to find that it does absolutely nothing for your hair? That is completely normal. Everyone’s hair has different needs, and understanding porosity can help you make sense of yours.

Porosity comes up a lot in hair care. You may have heard people talk about low-, medium- and high-porosity hair. But what do those terms actually mean? How can you tell which type you have, and how can that help you choose your products?

What is hair porosity?

Put simply, porosity describes the structure of a hair strand’s outer layer. This layer is made up of overlapping cells arranged rather like roof tiles. Their condition and the way they sit have a big influence on porosity. When the cuticles lie close together, the surface is usually smoother and better able to protect the inside of the strand from moisture loss. When they are raised, damaged or uneven, hair may absorb water more easily but also lose it more quickly. Porosity is only part of the picture, though. Strand thickness, curl pattern, your care routine and the environment all affect how your hair behaves. Porosity can even vary along a single strand. New growth may be in better condition than the ends, which have been exposed to wear and tear for much longer. That is why hair does not always fit neatly into one category.

Hair porosity is usually divided into three broad types:

  • Low porosity — the cuticles lie tightly against the strand, helping it retain moisture and look well conditioned.
  • Medium porosity — hair falls somewhere between the other two types and can have a mix of needs.
  • High porosity — the surface is generally more uneven, which can go hand in hand with frizz, roughness and broken ends.

Low-porosity hair: what to look for and how to care for it

One of the most recognisable features of low-porosity hair is its smoothness and often natural shine. It can feel soft, with strands that fall freely rather than clumping together, and tends to hold on to moisture well. That does not mean it is always perfectly smooth, straight or easy to manage. Low-porosity hair can be straight, wavy or curly, and its appearance also depends on the structure of the individual strands and how you care for them. Low porosity is not the same as having fine hair or fewer strands. This hair type can be fine and delicate, but it can also be thick, strong and very dense.

Low-porosity hair often takes a while to dry, but porosity alone does not determine drying time. Strand thickness, hair length, temperature and humidity all play a part. Thick, dense hair can take hours to dry, while fine hair with less density may dry much faster. Drying time on its own is therefore not enough to tell you your porosity.

Low-porosity hair can lose volume easily, especially when the strands are fine or delicate. Too much conditioner, hair mask, oil or leave-in product can make it look flat and feel heavy. It may even look greasy. Some products leave a coating that builds up over time, making hair look less fresh, dull or limp, or feel sticky. More thorough cleansing of the hair and scalp, along with using less product, can help. Keep in mind, however, that low porosity itself does not make your scalp produce more oil. Sebum production mainly depends on your individual physiology, hormones and sebaceous glands.

Caring for low-porosity hair is largely about finding the right balance between cleansing and conditioning. Thorough scalp cleansing matters because a build-up of oil, dirt and product residue can take away your hair’s lightness and natural shine. For regular washing, a moderately cleansing shampoo can clean the scalp and lengths effectively without drying them out too much. If your hair feels weighed down or sticky, or you struggle to get lift at the roots, a stronger clarifying shampoo may help when needed.

Remember: even if you are not experiencing these issues, it is worth using a scalp exfoliant every 1–2 weeks.

How often you wash should mainly depend on how quickly your scalp gets oily and how it responds to the products you use.

Lightweight formulas often work well for low-porosity hair, particularly when it is fine or easily weighed down. They can smooth the surface without sacrificing volume. Conditioner is usually best applied from ear level down to the ends, keeping it off the scalp unless the product is specifically designed for scalp use too. Still, not all low-porosity hair needs only lightweight products. Thick, dense or curly hair may respond well to richer conditioners and masks. Pay attention to the results: a product that is too rich can weigh hair down, while one that is too light may not provide enough smoothing or protection.

The same thinking applies to hair oiling. Oils can smooth the strands, reduce friction and help limit some of the damage caused by washing and detangling. A small amount on the ends can also improve their appearance and make styling easier. Too much, however, can leave hair flat and mean you need a more thorough cleanse.

Despite what you may have heard, low-porosity hair does not have to avoid silicones or every heavier oil. The issue may be how much you use, the overall formula or how often you apply it, rather than the ingredient itself. Instead of putting ingredients into strict “allowed” and “banned” categories, notice whether a product makes your hair softer, more flexible, shinier and easier to style, or simply weighs it down.

Medium-porosity hair: finding your balance

Medium-porosity hair has cuticles that are slightly raised rather than lying as tightly against the strand as they do in low-porosity hair. It generally absorbs and releases water at a moderate rate and responds fairly well to different hair care products. Often described as the middle ground between low and high porosity, it shares characteristics of both. It can look smooth and shiny while still being prone to frizz, dry lengths or a loss of softness, especially after heat styling, colouring, bleaching or an unsuitable routine. Remember that porosity does not tell you how thick or dense your hair is. Medium-porosity hair can be fine and delicate or thick, dense and strong, and it can be straight, wavy or curly.

This hair type can have quite a varied appearance. It is often relatively smooth, although its surface may not be as consistently even as that of low-porosity hair. Mild frizz can appear in humid weather, after drying without suitable conditioning or when the strands are rubbed. Waves and curls with medium porosity may lose definition when they are dry or not getting the care they need. With the right routine, they can feel flexible, bouncy and soft, and hold up well to everyday wear.

Medium-porosity hair is often considered fairly easy to care for because it tends to respond well to a wide range of products. The main challenge is finding a balance between moisture, smoothness and a lightweight feel. Fine strands usually do better with lighter formulas, while thick, dense, wavy or curly hair may need richer conditioners and smoothing products.

Base your washing schedule on your scalp, because the porosity of your lengths does not determine how much oil your scalp produces. Medium-porosity hair can get oily quickly or stay fresh for several days. After washing, use a conditioner to help detangle, smooth the surface and reduce friction between the strands. Apply it mainly to the lengths and ends, which are most exposed to dryness and mechanical damage.

A balance of proteins, emollients and humectants, sometimes called PEH balance, plays an important role in caring for medium-porosity hair. Proteins, such as hydrolysed keratin, wheat protein or silk protein, can improve hair’s appearance, make it feel more resilient and form a protective coating on the strands. They can be particularly useful in some formulas for weakened or damaged hair. Too much protein, or a product that does not suit your hair, can leave it stiff, rough or difficult to style. That does not make proteins harmful; it means you need to adjust how often you use them to your hair’s response. Emollients, including oils, butters, silicones and certain esters, help smooth the hair, reduce friction and limit moisture loss. They can improve softness, shine and manageability while helping to control frizz. Humectants, such as glycerin, panthenol and certain sugars, attract and bind water and can help maintain moisture levels.

Remember: after using humectants, follow with an emollient to help keep moisture in. Otherwise, your hair may end up looking dry.

How these ingredients perform also depends on the product’s overall formula.

Medium-porosity hair often responds well to oiling. The right oils can smooth the surface, reduce friction and improve the look of the ends. You can apply oil before washing, or use a small amount on the ends afterwards. Almond, avocado and macadamia oils are options worth trying for this hair type.

Medium-porosity hair can be more prone to frizz than low-porosity hair. Humid weather and vigorous towel drying can make it more noticeable. Porosity is not the only factor, though: your natural curl pattern, hair condition, drying technique and choice of products all matter. To help keep frizz under control, gently blot your hair with a soft towel, avoid rubbing it, use a conditioner that makes detangling easier and choose smoothing products that suit your hair. Styling creams, gels or mousses can help define waves and curls. Straight hair may do better with lighter products that smooth without weighing it down.

High-porosity hair: moisture, smoothness and protection

High-porosity hair has cuticles that are more raised, lifted or damaged than those of the other porosity types. Its surface is usually less smooth, and the strand may be more vulnerable to external stress. It often takes in water relatively quickly but can also release moisture more readily, leaving it dry to the touch, rough or less flexible after washing or drying. That does not mean every high-porosity strand always dries quickly. This hair type needs particular attention: conditioning matters, but so do preventing damage, protecting the lengths and limiting moisture loss. High porosity is often associated with damage from bleaching, colouring, frequent heat styling or repeated mechanical stress. The hair itself can be fine or thick, sparse or dense, and straight, wavy or curly. Porosity does not tell you the thickness of each strand, how many strands you have or your curl pattern.

High-porosity hair often looks less smooth and more matte. The surface may feel rough, making it harder to detangle. However, it does not always have to look dull or feel unpleasant. With suitable care, it can be soft, shiny and flexible, although maintaining those results may take more attention. Frizz is another common feature. Changes in humidity can make the strands harder to manage, with flyaways and a less smooth finish. Waves and curls may become frizzy and lose definition at the same time. Straight hair may look dry, puffy or uneven along the lengths, especially at the ends.

High-porosity hair is often more prone to dryness, particularly through the lengths and ends. It can feel rough, stiff or less bouncy and may tangle easily. Sometimes it seems to need constant conditioning, yet still does not feel soft enough despite using plenty of products. Regular smoothing, reducing friction and protecting it from further wear are therefore particularly important.

A routine for high-porosity hair should focus on improving its condition while limiting further damage. Start with suitable cleansing for both the scalp and hair. Dry lengths are not a reason to stop washing regularly or avoid stronger cleansing shampoos altogether. Choose shampoo mainly around your scalp’s needs, rather than the porosity of your lengths. An oily scalp needs regular cleansing; a sensitive or dry scalp may need a formula that cleans effectively without unnecessary irritation. When washing, focus on the scalp and avoid vigorously rubbing the lengths, as wet strands can be more vulnerable to mechanical damage. Gently distribute the lather and let it rinse down through the hair.

Conditioners and masks that add slip, smooth the strands and make detangling easier are especially useful for high-porosity hair. Emollient-rich products often work well because they can form a coating on the hair’s surface, reducing friction and moisture loss. Depending on what your hair needs, you might choose a richer mask, a smoothing conditioner or a product designed for dry or damaged hair. That does not mean every thick, heavy formula will suit you. Fine, high-porosity strands can still lose volume easily, so products that smooth without excessive weight may work better. Thick, dense and curly hair often needs richer conditioning to help control frizz and maintain curl definition.

Emollients have an important place in a high-porosity routine. Consider oiling before washing to help limit damage from cleansing and friction. A small amount of serum or oil on the ends, applied morning and evening, should also be a regular part of your routine. Oils do not all perform in the same way, so pay attention to how your hair responds. Flaxseed, black seed and grapeseed oils are options to consider.

High-porosity hair may also benefit from proteins such as keratin, elastin, collagen or silk. These have larger molecules and can be a better fit for this hair type than hydrolysed proteins. In hair care products, they can help fill small gaps on the surface of the strand, which is especially useful when hair is damaged. That does not mean you need protein at every wash, or that using more will give you better results. If a protein product leaves your hair stiff, rough, tangled or hard to style, use it less often.

Tangling and breakage are common challenges for high-porosity hair. An uneven surface can cause strands to rub against one another, catch on a brush or comb and form stubborn knots. Long hair is especially exposed, as the ends have been through years of wear. Repeated pulling during detangling can make matters worse. Work gently from the ends upwards, moving towards the roots a little at a time. Detangling conditioners and brushes suited to your hair type can help. Avoid yanking apart knots or rubbing your hair hard with a towel. You can also reduce friction while you sleep by using a silk pillowcase and wearing loose styles that do not pull on the strands. These habits can help limit further mechanical damage.

High-porosity hair often responds well to smoothing products and treatments that protect the ends. Silicones can be useful here, forming a conditioning layer on the surface of the hair. More substantial silicones such as dimethicone, amodimethicone or phenyl trimethicone may work well. There is also no need to automatically avoid heavier oils or plant butters if your hair responds well to them.

How can you check your hair porosity at home?

You may have come across the float test online: place a single hair in a glass of water and see whether it sinks or stays on the surface. Although it features in many hair care guides, it is not a reliable way to determine porosity conclusively. Other factors affect how a strand behaves in water, so it is best not to base your product choices solely on this experiment.

A more useful approach is to observe your hair day to day. Notice how quickly it dries, whether it tangles easily and how it reacts to humidity, or try our hair porosity test. If you are unsure, especially after colouring or bleaching, an experienced hairdresser or trichologist can help assess its condition. Above all, pay attention to how your hair responds to care and gradually choose products that meet its actual needs.

Can your hair porosity change?

Yes, although it helps to distinguish your hair’s natural characteristics from its current condition. Porosity is linked to the outer layer of the strand, which can change as a result of bleaching, colouring, heat styling or mechanical damage. Hair that was once smooth and shiny, with low porosity, can become rougher, duller and more prone to frizz as its porosity increases. You can also have different porosity levels along your hair: the roots may be in better condition than lengths and ends that have been exposed to years of treatments.

Suitable care can smooth the surface, improve appearance and make detangling easier, but it does not permanently reverse every kind of damage. If your hair is severely damaged, a cut may be the best option. Look at where the most damaged section begins and trim a little above that point. Otherwise, your routine may not be enough, and the damage can travel further up the strand.

Bringing it all together

Porosity can help you choose products and plan your routine. Low-porosity hair often responds better to lighter formulas, high-porosity hair may need richer products to smooth the strands and control frizz, and medium-porosity hair needs care that reflects its current condition. None of this means you have to follow a rigid set of rules for your hair type.

Every head of hair is different. Consider strand thickness, curl pattern, everyday habits and your own preferences alongside porosity. Notice which products help your hair stay soft and shiny, and which leave it heavy or rough. Over time, you will find it easier to balance what your hair needs with the results you enjoy. A good routine comes from getting to know your hair and making thoughtful choices about how you care for it each day.

← Back to the blog