12/10/2025
A recent study has revealed why hair turns gray with age and offers new hope for reversing this process. The research focuses on melanocyte stem cells (McSCs), the cells responsible for hair color. As we age, these cells lose their ability to move and transition between states, causing them to become "stuck" in hair follicles and unable to produce pigment. Without this pigment, hair grows gray.
McSCs are a type of stem cell found in hair follicles. They produce melanocytes, which are responsible for giving hair its color. In a healthy hair cycle, these stem cells shift between dormant and active states to regenerate and create new hair color. However, as people age, these cells lose their mobility, becoming trapped in the follicle's bulge area, where they can no longer mature into melanocytes. This is what causes the graying of hair.
Using a mouse model, researchers from NYU Grossman School of Medicine observed that as mice aged, the number of McSCs that became immobile increased. Younger mice had only 15% of these cells trapped, while older mice saw nearly half become stuck. The study found that this loss of mobility, not just aging, is the key factor in graying hair.
The study suggests that restoring McSCs’ ability to move and switch roles could help prevent or even reverse graying. Researchers now hope to find ways to reawaken the mobility of these cells, potentially leading to treatments for gray hair.
