The shelf life of an unopened bottle is 6 months since the manufacturing date. Once opened, the glue can last up to 2 months under the proper storage conditions (tightly capped, in the sealed pouch in a cool place), but we recommend using it within one month after opening because no matter how ideal is the storage the nature of these glues is such that they are subject to aging, so the fresher the glue, the better. Please see the production and expiry dates on the package.
As for Premium Pro, its shelf life is extended to 9 months when unopened, and up to 3 months once opened.
Inside each glue package, you'll find a special sticker, where you can indicate the date of opening to always remember when to replace the bottle with a new one.