01 / THE DETAILS
The outer layer and the inner structure
The cuticle forms overlapping protective layers around the cortex. The cortex contains most of the fibre’s keratin and pigment. Some hair fibres also have a medulla, but it is not the main target of everyday cosmetic services.
A damaged cuticle can increase roughness, friction and tangling. Internal change can affect how hair stretches or resists breakage. These are related but not identical problems.
02 / THE DETAILS
Several bonds matter
Disulfide crosslinks contribute to keratin structure, while hydrogen and ionic interactions also influence hair behaviour. Moisture, heat and chemical processes can change the balance of interactions.
The phrase “broken bonds” is useful shorthand, but it can hide complex chemistry. Different laboratory tests measure different outcomes, and a glossy finish cannot tell us exactly which bonds have changed.
03 / THE DETAILS
What that means in the salon
Conditioners can improve surface feel. Certain treatments aim at mechanical performance or chemical interactions. Neither can turn repeatedly bleached hair back into untouched virgin fibre.
The most useful approach combines thoughtful services, sensible styling and realistic maintenance.
Further reading
Research and technical reference:
View the published scientific source ↗Hair care product claims and individual responses vary. This article is educational and does not replace a personal professional assessment.