Each sachet of Evivo is specially packed and sealed in an airtight sachet that keeps out air, moisture, and light, completely protecting the live bacteria. Keep it in the refrigerator or freezer until you're ready to use it. And no worries if you forget to take Evivo out of the freezer. Evivo can be used straight from the freezer. Evivo will keep in the freezer for up to one year or in the refrigerator for up to one month.