We recommend that you use the adhesive within 6-8 weeks of the purchase and opening date. The fresher the adhesive, the better the results. You should keep adhesives upright in its pouch with silica bag in a cool dry room . And shake well (about 2min) before each use and shake between each drop. If you have very high humidity and temperature, and you lash minimum 4 clients per day, that means you opening bottle of adhesive quiet often, you should replace bottle every 3-4 weeks. When you shake bottle of glue, make sure you remove lid, place glue pin in to the nozzle and shake it this way, this prevents glue go in to the cup/lid.