25/03/2026
Each time a new growth cycle begins, the follicle reaches a decision point. Will the new strand grow with pigment, or without it?
Inside the follicle, there are two key zones. At the bottom is the bulb, where the new hair strand forms and pigment is produced. Higher up is the niche, where melanocyte stem cells are stored and prepared for the next cycle.
As long as the signalling between these zones works properly, hair grows with colour. When that process is disrupted, a new strand may grow without pigment.
That is why grey hair is not simply about age. It is also about cellular timing, signalling, and how the follicle functions as a system.
Follow for more explanations of the biology behind greying.