Our refills contain 4.5g of Lip Balm and we would estimate this to last a person roughly 1 month. We find that most people use it daily, and re-apply a couple of times throughout the day, whenever their lips start to feel a bit dry. However, use it whenever you like, everyone is different!
As for the shelf life, it will last up to 12 months! We recommend storing it in a cool, dry place, away from direct sunlight.