@glolef The manufacturer says to keep it refrigerated, until your first dose. After removing the pen from the refrigerator, ideally at least 45 minutes prior to the injection, then it is not necessary to refrigerate again. You can keep it on the shelf for the remainder of the 30 days that the manufacturer says the medication remains stable (and after which, Tymlos says to discard any remaining medication, as the ingredients can start to degrade). The only time you would consider putting it back into the refrigerator would be if you were traveling in the pen has the chance of remaining in a hot car. In that case, it is recommended that you put it in a cooler.