The manufacturer has done an internal stability test showing that our Advanced NMN will maintain its purity over the period of 10 weeks in a consistent 104-degree Fahrenheit temperature. Because of this, and because we use insulating materials, we know that it does not need to be shipped in a cooled container while in transit to your home. We guarantee that your Advanced NMN shipments will meet our high purity standards when you receive them or your money back. While NMN does degrade slowly in a consistent heat, it does take many months. If you plan on storing NMN for long periods of time (possibly years), we suggest putting the NMN jars in a vacuum-sealed plastic bag and then putting it in the freezer. But if you will be taking your NMN within a month or two, it should be fine when stored in a dark cool cabinet in your home.