Physico-chemical properties of modern cosmetics for styling and their effect on hair structure

The study investigates how modern hair styling cosmetics interact with and affect hair structure, especially under repeated stress. These products don't biologically repair hair but reorganize its surface and stabilize its structure through surface deposition and molecular penetration. The effectiveness of these cosmetics is influenced by the hair's existing damage, with factors like surface charge and porosity being crucial. Modern formulations use polymers, proteins, and bioinspired ingredients to form films that fill microdefects and reduce friction, while low-molecular-weight agents penetrate the cortex to restore crosslink density. The study emphasizes the need for a balance between penetration and structural reinforcement, as increased porosity can enhance agent uptake but reduce fiber stability. This research provides insights into how styling products reshape hair structure, moving from restorative claims to controlled structural compensation, and highlights the importance of tailoring products to specific hair damage profiles for improved outcomes.