Why does hair turn gray?

Short answer

When hair follicles make less melanin pigment, newly growing hair appears lighter or gray.

How it works

Age, genetics, and individual traits matter. The growing part changes color from the root rather than one hair bleaching instantly along its length.

Key point

The practical point is this: The growing part changes color from the root rather than one hair bleaching instantly along its length.

References

• National Institute of Arthritis and Musculoskeletal and Skin Diseases: Learning about skin
• National Institute of Dental and Craniofacial Research: Oral health