Permanent hair straightening is a process by which the structure of your hair is altered to give you pin straight hair. The chemicals used in this process permanently break the bonds in your hair shaft. Heat is applied to restructure your hair, and more chemicals are used to seal the newly formed bonds.
While this process causes more damage than hair smoothing, it can straighten even the curliest of hair types and is permanent, meaning that the treated hair will remain straight until your natural hair grows out. Permanent hair straightening is also known as ‘Japanese straightening.’