Not Medical Advice: No, it is not contagious.
According to Jeffrey Benabio, MD, a dermatologist at Kaiser Permanente in San Diego, hair goes gray when color-producing cells stop producing pigment. Naturally occurring hydrogen peroxide can also build up in the hair, bleaching the color.
Typically, white people start going gray in their mid-30s, Asians in their late 30s, and African-Americans in their mid-40s. Half of all people have a significant amount of gray hair by the time they turn 50.
A white person is considered to be prematurely gray if his or her hair turns gray by age 20; gray before 30 is early for African-Americans.
Scientists don’t know exactly why some people go gray early, but genes play a large role.
Also, a vitamin B-12 deficiency or problems with your pituitary or thyroid gland can cause premature graying that’s reversible if the problem is corrected.
Check out the Top Ten Hair Myths, shared by Hair-styles.org.