Your hair's ability to absorb and retain moisture is referred to as hair porosity, and it affects how well oils and moisture pass through the cuticle, the outermost protective layer of the hair. Hair porosity is largely influenced by genetics, hair care, and styling practices.

Each strand of hair on your head is like a well made boat. A well made boat will float on water, but a poorly made boat will sink quickly. The same is true of your hair when it comes to testing for porosity. 

To test your hair for porosity, wash hair with shampoo, skipping the conditioner. Hair should be air dried with no product. Once dry, dip a few strands of clean hair into a glass of room temperature water for fifteen minutes to determine hair porosity.

High Porosity: Unhealthy hair is high in porosity and will sink to the bottom of a glass, as it easily and quickly absorbs the water. Hair that is high in porosity absorbs more moisture that it is able to retain. This type of hair will take longer to dry and will "soak up" color treatments and moisture. Hair may appear dull and frizzy and may tangle easily. Hair that is high in porosity requires conditioning treatments with protein and frequent breaks from chemical and heated treatments. 

Medium Porosity: Hair that lands in the middle of the glass, that is it neither floats nor sinks has a medium-level porosity and is considered healthy. Hair with medium porosity withstands most color services and requires minimal maintenance, as the cuticle is slightly raised and allows moisture to penetrate to the cortex, the middle layer of the hair follicle. While this type of hair is considered healthy, major bleaching or chemical services should be avoided.

Low Porosity: Hair that is low in porosity will float at the top of the glass. This type of hair does not allow moisture to be absorbed easily, and under a microscope the cuticles may overlap. This type of hair repels water and may be difficult to wash. Hair that is low in porosity will also resist conditioners and processing. Low porosity in hair is often genetic in nature and not a result of chemical and heating overuse. Hair with low porosity can be made healthier with moisturized treatments. 

Understanding hair porosity allows your to customize styling practices to fit the needs of your hair. How does your hair measure in the glass? Share your results with our hair experts! 

To Learn More, Visit