Apply benzoyl peroxide to the areas of your skin affected by acne. Avoid getting this medication into your eyes, inside your nose or mouth, or on any areas of broken skin since it may cause irritation. If this occurs, flush the area with plenty of water. Benzoyl peroxide may bleach hair or fabrics. Use carefully, and avoid contact with hair, clothing, and furnishings. If using cleansers containing benzoyl peroxide, wet the affected area. Gently rub the cleanser into the skin for 10-20 seconds. Work into a full lather and rinse thoroughly and then pat dry.