Recommended shelf life is how long a product stays fresh after its made. Shelf life varies by product type. Fragrances should be used within 3 years to enjoy the freshest scent. Other products, like skin cream or mascara, have a PERIOD AFTER OPENING symbol on the package: a small jar with a number inside followed by the letter M. This refers to the number of months, after opening, that product can be used safely. Expiration dates only appear on products with active ingredients, like antiperspirants or sunscreens. The expiration date is the date after which the active ingredient is no longer considered effective.