Question: I have a full head of hair, but am going grey. Is there danger associated with hair dyes?
Dr. Hibberd's answer:
Your hair has lost its pigment and adding pigment on the surface from hair dyes usually is quite safe. Excessive dying of your hair may result in scalp irritation and hair loss, but the newer dyes are now far safer and well tolerated than the older dyes that did have adverse effects on the hair and scalp.
I would avoid overuse of hair-color products or permanents, as they will often make your hair break prematurely and become quite brittle, sometimes resulting in hair loss.