Tired of dry, frizzy, or flat hair? Learn to work with your hair porosity

“Hair porosity simply refers to your hair’s ability to absorb and retain moisture. Every strand of hair is porous to an extent, but the degree of porosity – whether low, medium or high – varies from person to person. This depends primarily on how tightly or loosely the cuticle layer, which is the outermost layer of your hair shaft, is arranged.

People with high porosity hair will find that their hair cuticles are open or raised, which tends to absorb moisture quickly, but also loses moisture just as fast. This means their hair is particularly vulnerable to external stressors such as chemical treatments, excessive heat styling and environmental exposure. It often lacks shine, elasticity and strength. Many of my clients with highly porous hair also struggle with rapid colour fading and styling that doesn’t last. In more severe cases, hair may break off easily and begin to feel cotton-like and weak. Unfortunately, this type of damage is usually irreversible and can be emotionally distressing to manage, especially if it affects self-esteem and confidence.

On the other hand, low porosity hair means hair cuticles are tightly packed and more resistant to moisture, which can make it harder for water, oils or treatments to penetrate effectively. Your hair might take a long time to dry, and hair products are not absorbed as easily.

Porosity is not just determined by genetics or age. It is also heavily influenced by hair texture, chemical processes and heat damage. Bleaching, for example, significantly increases hair porosity. Even a basic colour or perm job can transform hair from low to medium porosity. Those with fine hair, which has about five to seven cuticle layers, will notice it is more porous than coarse hair, which can have up to twelve layers. Curly or wavy textures are also naturally more porous because their cuticles tend to be more lifted than straight hair.

Working with what you have

Understanding your hair porosity allows you to choose the right kinds of products and treatments for the best results.

For example, high porosity hair benefits from products that are rich, moisturising and able to seal in hydration while protecting against breakage. These products help compensate for the hair’s tendency to lose moisture quickly. On the other hand, low porosity hair may look flat or greasy if heavy products are used, so it is better supported by lighter formulations that will not weigh it down or cause buildup. Adjusting your hair routine according to porosity can dramatically improve how your hair looks, feels and behaves over time.

In Singapore, our high humidity can also influence how hair behaves in relation to its porosity. While humidity does not actually change your hair’s porosity, it can amplify its effects. High porosity hair soaks up excess moisture from the air and can become frizzy or puffy. On the other hand, low porosity hair may resist humidity but end up feeling limp or greasy, especially if there’s product residue on the scalp or hair shaft. That’s why I often advise my clients to tweak their haircare products with the climate in mind, like using anti-frizz solutions for high porosity hair and clarifying cleansers for low porosity hair.” - Leonica K, founder and principal trichologist at Leonica K Trichology.