I believe that the shelf life begins from the day that the product is bottled. Because even if it hasn't been opened, some air and bacteria would have been trapped during the bottling/packaging stage. Typically the preservatives in the cream keep the bacteria from growing, but over time, the bacteria will find a way to multiply and cause the product to go bad. The shelf life of products will most likely vary quite a bit depending on what preservatives are used and how the cream is packaged. Even if there is no expiration date, there should be some sort of batch number printed either on the bottle or box. You can always contact the manufacturer and they can tell you when your batch was created and what the shelf life is based on their tests.