Hair Porosity 101: What It Is and Why It Matters for Your Routine.

Written by: Rhonda Davis 

You've probably heard of low and high porosity hair but what does it really mean and how should you care for it? For starters, hair porosity refers to the condition of the cuticle and how well a strand absorbs and holds onto water, product and treatments. If you recall in our previous blog post about hair texture ( READ IT HERE ), the hair is comprised of many layers and the cuticle is the outer protective layer of the hair fiber. Because it is a protective layer, the cuticle is what receives the brunt of our daily manipulation: brushing, twisting, heat and chemical processing, which leads to further damage. This damage can be minimal or excessive and is visible under a microscope as holes or gaps in the cuticle. 

Normal or medium porosity hair strikes a healthy balance, absorbing water at a predictable rate and responding well to chemical treatments like color or relaxers. Low porosity hair has a tightly sealed, flat cuticle that resists water and product absorption. This shows up as hair that takes a long time to get wet or dry, products that sit on the surface instead of absorbing in and chemical treatments that underperform. And of course high porosity hair is the opposite: the cuticle is lifted or compromised often from curl pattern, mechanical stress like daily brushing or damage from coloring and UV exposure. This causes highly porous hair to absorb water quickly but loses it just as fast, leading to dryness, frizz and a higher risk of breakage.

While cosmetic chemists have access to tests to analyze hair samples, consumers can find out if they have normal/medium, low or high porosity hair by simply trying the spray test at home. The spray test allows you to visually see how water performs on the hairs surface. Simply fill a spray bottle with water and spray the hair. If the water beads, that suggests low porosity, however if the water is absorbed almost instantly, that suggests high porosity. Please note that a human head can have a combination of low, medium and high porosity hair due to years of damage and manipulation.

AYIRA Beauty products are specially formulated with a combination of amino acids and peptides to help fill in the gaps left by a lifted or damaged cuticle. Our products also have an acidic pH (4.4 - 5.5) which is ideal for all hair types, no matter if low or high porosity. We also along with a special blend of lightweight and richer oils to help seal the hair. Those with low porosity hair can also benefit most from our products by using tools such as steamers to open the cuticle just enough to allow our products into the hair.

Sources

1. Syed, A. "Correlating Porosity to Tensile Strength." Cosmetics & Toiletries, 117(11), 57-62 (2002).
2. Dawber, R. "Hair: Its Structure and Response to Cosmetic Preparation." Clinics in Dermatology, 14, 105-113 (1996).
3. Davis-Sivasothy, The Science of Black Hair (Saja Publishing Company, Texas, 2011), pp. 47-50, 78-91.
   
4. Hessefort, Z., Holland, B.T., and Cloud, R.W. "True Porosity Measurement: A New Way to Study Hair Damage Mechanisms." Journal of Cosmetic Science, 59, 263-289 (2008).
   
5. Evans, T. "Adsorption Properties of Hair," in Practical Modern Hair Science, T. Evans and R. Wickett, Eds. (Allured Business Media, Illinois, 2012), pp. 333-365.