If you are using any skin care product for the first time, particularly if you have a history of extreme skin sensitivity, we suggest you conduct a self-patch test to check for the possibility of an adverse reaction. Simply apply a small amount of product on the inside of your arm or underneath your jaw line. Allow at least 24 hours to pass before checking the area. If no reaction has occurred, the product should be safe for you to use as directed. If a reaction does occur, do not use the product.