Before using this product, always make a preliminary patch test to see if you are or have become allergic/sensitive to any ingredient. Simply mix a small amount of the product as described below and apply to about a one-inch square area of inner arm. After ten minutes, wash the mixture off with cold water. Wait twenty-four hours. If redness, irritation or eruption appears, do not use the product. Lightens Excess Dark Hair Lightens dark hair on face, arms, body and brow.