A hair serum is a topical treatment applied to hair to improve its appearance and health. Kiehl's Hair Serum is a particular brand of hair serum that is known for its nourishing and revitalizing properties.
Hair serums are often used to address specific hair concerns, such as dryness, frizz, or damage. Kiehl's Hair Serum contains a blend of natural ingredients like rosemary leaf extract and olive fruit oil that work together to hydrate, strengthen, and protect hair.