Store newly purchased, unopened bottles of insulin in the refrigerator in their original carton to keep them clean and protected from light. When you're ready to use a bottle of insulin, you can remove it from the fridge and generally keep it at room temperature (below 86 degrees F) for up to one month.

But the sterility and potency of an opened bottle of insulin are affected by the number of insulin injections per day, the volume of insulin remaining in the bottle and exposure to light and agitation. For this reason, it's important to discuss your insulin dosage and storage—and review patient information available on the insulin manufacturer’s website—with the doctor treating your diabetes.

You should also check opened bottles of insulin carefully for discoloration or particles. Never store insulin in the freezer or in direct sunlight and always be sure to check the expiration date.

By Joyce A. Generali, M.S. FASHP, R.Ph., director of the University of Kansas Drug Information Center and the author of The Pharmacy Technician’s Pocket Drug Reference

From our sister publication, Diabetes Focus, Summer 2011

Publication Review By: the Editorial Staff at

Published: 24 Apr 2011

Last Modified: 11 Sep 2015