Hair Porosity Explained – and How to Formulate for It

Hair porosity is one of the most talked about topics in hair care, yet it is also one of the most misunderstood. It is often simplified into basic categories without fully explaining what is actually happening at a fibre level, which can lead to incorrect product choices and ineffective formulation decisions.

This educational document has been created to provide a scientifically accurate understanding of hair porosity, focusing on how the structure of the hair fibre influences the way it interacts with water, conditioning agents, and formulation systems. Rather than relying on oversimplified explanations, this guide breaks down the physical and chemical mechanisms that determine porosity and how these directly impact product performance.

You will gain a clear understanding of how low, medium, and high porosity hair behave, what structural changes cause these differences, and how to formulate products that work with the fibre rather than against it. This includes ingredient selection, deposition behaviour, moisture management, and the role of molecular size and charge in formulation design.

This resource is designed for formulators, brand owners, and anyone looking to deepen their knowledge beyond surface-level hair care advice. Every concept has been written with scientific accuracy in mind, while still being practical and applicable to real-world formulation.