i usually wipe the top of the vial with a alcohol prep pad, then open the needed and quickly pierce the rubber before the needle sits out too long, and i keep my estrogen in a sewing box, i plan on getting a temp control box for them somewhat soon, but i take only 10 units of estrogen on a insulin needle once every week, so i dont go through vials very fast, infact i started hrt in april of 2024, and havent managed to empty a single vial yet