What causes premature greying of hair

You may have heard this before, but grey hair can turn black again naturally. It's a myth that all colouring will go away if you bleach it multiple times or put chemicals on your head!

What causes premature greying of hair
You may have heard this before, but grey hair can turn black again naturally. It's a myth that all colouring will go away if you bleach it multiple times or put chemicals on your head!