SmellWell  Original and XL last for up to 6 months or more, from when they are unsealed. Lifespan may vary depending on what they are used for. Generally, life expectancy is shortened when used in areas with high relative humidity. If they are used in a pair of sweaty hockey gloves, they can work harder than in a pair of sneakers. However, placing your SmellWell where air can circulate refreshes them again.