Insulin Storage and Handling Guidelines

Storage Requirements

Unopened insulin vials should be stored in a refrigerator between 36-46°F (2-8°C) to maintain potency, and kept in their original carton to protect from light 1, 2
Once opened, insulin vials should be stored at room temperature (59-86°F/15-30°C) and discarded after 28 days, regardless of the amount remaining in the vial 1

Before each use, inspect vials for changes in appearance, such as clumping, frosting, precipitation, or changes in clarity/color, which may indicate loss of potency 2, 3
Rapid and short-acting insulins should appear clear, while intermediate and long-acting insulins should appear uniformly cloudy 2, 3
If unexplained high blood glucose occurs, consider replacing the insulin vial 3
Never use insulin that shows visible changes in appearance regardless of storage history 2

Insulin should be avoided from extreme temperatures (<36°F or >86°F) and stored away from direct heat, sunlight, and excessive agitation 1, 2
Use insulated bags with cooling packs when traveling in hot conditions 1
Room temperature storage (below 86°F/30°C) for 4 days is generally within acceptable limits for most insulins, but insulin that has been left at room temperature for an extended period may have reduced potency 2, 3

Always keep a spare vial of each insulin type used 2
Most prefilled pens should not be refrigerated once opened and should be discarded after 28 days (or according to manufacturer guidelines) 1
Insulin cartridges should not be discarded until 28 days after opening (or according to manufacturer guidelines) 1
Never store insulin pens with needle attached 1
Don't freeze insulin as freezing destroys insulin molecules 2

The American Diabetes Association recommends that unopened insulin vials should be refrigerated at temperatures between 36-46°F (2-8°C) and insulin in use may be kept at room temperature (below 86°F/30°C) to limit local irritation at injection sites, with extreme temperatures (<36°F or >86°F) and excess agitation avoided as they can cause loss of potency, clumping, frosting, or precipitation 2
The American Diabetes Association guidelines emphasize the importance of proper insulin storage and handling to maintain its potency and effectiveness, and provide recommendations for storage, inspection, and replacement of insulin 2