Gray hair results from reduced melanin production in hair follicles, primarily due to aging melanocyte stem cell depletion in the hair bulb.

Biological Mechanisms

Hair color depends on melanin synthesized by melanocytes. Aging triggers oxidative stress and DNA damage, diminishing melanocyte stem cells' ability to regenerate. This process follows a stochastic model where melanocyte exhaustion leads to gradual graying.

Core Gray Hair Model

The predominant model involves melanocyte stem cell kinetics: over time, cumulative damage depletes reservoir cells in the bulge region, reducing pigment transfer to keratinocytes. Key stages include initiation (reduced tyrosinase activity) and progression (apoptosis of pigment cells).

Influencing Factors

• Genetics: MC1R gene variants accelerate onset.
• Age: Incidence rises sharply post-30s, with 50% graying by 50.
• Stress: Chronic stress increases cortisol, promoting inflammation and premature depletion.
• Nutrition: Deficiencies in copper, vitamin B12, or iron exacerbate loss.

Professional Insights

Gray hair is largely irreversible, but mitigating oxidative stress through balanced diet and stress management may slow progression. Consult dermatologists for personalized advice; avoid unverified treatments.