It depends on the user because everyone inhales the mist in a different way. Each disposable device should last between 450-500 inhalations. They recommend you take no more than 20 inhalations per hour. If you use it correctly, it’s ideally going to last 1-3 weeks. If you use it less often, depending on the variety you choose, it may last longer. The SOOTHE, when used only nightly before bed can last up to a month.