I have always been under the impression that insulin should always be refrigerated. I am seeing a patient that receives lantus QD and Novalog TID. she does not keep the pens that are being used, refrigerated, only the unused ones. Although even though they are not kept refrigerated, they do seem to keep her blood sugars under control. I wonder though if they were refrigerated would that make a big difference? I will call her physician if necessary. I only see her once a week, another nurse sees her the other 6 days. Since I am new with her, I don't want to start a problem but on the other hand, I don't want to do anything wrong either.