What is the chemical process that permanently alters the structure of hair?

The chemical process that permanently alters the structure of hair is permanent waving. This method involves the use of specific chemicals that break down the disulfide bonds in the hair's structure, allowing the hair to be reshaped. Once these bonds are broken, the hair can be reformed into new styles or shapes, such as curls or waves, which will last until the hair grows out or is cut.

Permanent waving is specifically designed to create lasting changes in the hair's texture and shape, unlike other processes such as hair bleaching or coloring, which typically only affect the color of the hair and not its structural integrity. Deep conditioning is primarily a conditioning treatment aimed at improving the hair's moisture and manageability, without altering its structural properties. Hence, the focus on permanent waving as the process that fundamentally changes the hair is clear, as it involves a transformation that is durable and deeply impacts the hair's composition.