What is the role of a keratin treatment in hair care?

The role of a keratin treatment in hair care is primarily to smooth and strengthen the hair. Keratin is a natural protein that makes up the structure of hair, and treatments designed to infuse keratin into the hair can significantly improve its texture and appearance.

These treatments work by coating the hair strands with keratin, which helps to fill in gaps and reduce frizz, resulting in a sleek, polished look. Additionally, because keratin can reinforce the hair's structural integrity, it also helps to minimize breakage and damage, leaving the hair looking healthier and more manageable.

With this understanding, the other options focus on different hair care goals that are not achieved through keratin treatments. Lightening hair color relates to chemical processes that change pigmentation, and while some treatments may lead to a temporary appearance of volume due to smoothing effects, keratin treatments do not inherently add volume to hair. Promoting hair growth is generally associated with other treatments or solutions that target the hair follicle and growth cycle, rather than merely altering the structure or appearance of existing hair.