Chemical peels, depending on their kind, can be applied to: The area around the mouth and chin (for vertical lines, or ‘smoker’s lines’) The forehead (for horizontal wrinkles) The cheeks (for brown spots, acne scars and fine wrinkles) The neck (for fine lines) The hands (for age spots and wrinkles) The back (for acne scars, if acne has not created open wounds) And, technically, other areas on the body where skin needs a collagen 'boost.'