How Long Can Insulin Be Out Of The Fridge?
Insulin therapy for diabetic people poses many challenges. Of course, injecting insulin multiple times a day is not fun. But the pain with injecting insulin is only a part of the struggle. The logistics of taking insulin can be time consuming and overwhelming for people with diabetes who are treated with insulin. When a person with diabetes takes insulin, leaving the house requires extra planning and preparation. Many people find traveling and even simply leaving the house for work, to run errands or to go out for a meal challenging because of confusion over how long can insulin be out of the fridge. Since insulin is so challenging to take and has major risks like hypoglycemia, there are medications that should be considered in type two diabetes before starting insulin.
Why do we refrigerate insulin?
Insulin is a peptide hormone used to lower blood sugar. Peptide hormones like insulin can spoil and no longer work if stored at incorrect temperatures. Insulin stored in the fridge is kept at a temperature that prevents spoiling longer than if kept at room temperature, 36°F to 46°F. It also protects insulin from being exposed to large fluctuations in the temperature. Very cold and very hot temperatures can quickly spoil insulin.
How long can insulin be out of the fridge?
Most insulin pens and vials can be stored out of the fridge at room temperature, below 86°F, for about 28 days. However, some pens and vials can be stored at room temperature for shorter or longer durations.
Some insulin vials and pens have different storage instructions when they are unopened than after they have been opened. It is important for patients to know what type of insulin they are taking and the storage recommendations for the specific type of insulin they are taking.
Insulin vials
Unopened insulin vials can be stored in the fridge until their expiration date. Opened vials can be stored in the fridge, too, but usually only for 28 days after opening.
These are the most common insulin vials used and they can be stored at room temperature for 28 days. After 28 days, opened insulin vials should be thrown away even if there is still insulin left in the vial.
Insulin glargine (Lantus, Basaglar, Semglee)
Insulin aspart (Novolog and Fiasp)
Insulin lispro (Humalog and Lyumjev)
These insulin vials have different storage instructions:
| Unopened Refrigerated | Unopened Room Temp | Opened Refrigerated | Opened Room Temp | |
| Insulin detemir (10mL Levemir U-100 vial) | Until expiration date | 42 days | 42 days | 42 days |
| Insulin degludec (10mL Tresiba U-100 vial) | Until expiration date | 56 days | 56 days | 56 days |
Insulin pens
Unopened insulin pens can be stored in the fridge until their expiration date. Open pens should not be refrigerated. Open pens should be kept at room temperature.
These insulin pens can be stored outside of the fridge for 28 days. After 28 days, opened insulin pens should be thrown away even if there is still insulin left in the pen.
Insulin glargine (Lantus, Basaglar, Semglee)
Insulin aspart (Novolog and Fiasp)
Insulin lispro (Humalog and Lyumjev)
These insulin pens have different storage instructions:
| Unopened Refrigerated | Unopened Room Temp | Opened Refrigerated | Opened Room Temp | |
| Insulin detemir (Levemir) | Until expiration date | 42 days | Do not refrigerate | 42 days |
| Insulin degludec (Tresiba FlexTouch) | Until expiration date | 56 days | 56 days | 56 days |
| Insulin glargine U-300 (Toujeo Solostar and Toujeo Max) | Until expiration date | 56 days | Do not refrigerate | 56 days |
How do I know if my insulin is spoiled?
It is important to always ensure that the insulin in the pen is a clear liquid. If it is cloudy, that may indicate that it is spoiled.
Sometimes insulin may be spoiled even if it looks normal. If the blood sugar is not going down as usual after a usual dose of insulin, that could mean that the insulin has spoiled or broken down. If insulin has been exposed to extreme heat or cold, it should be discarded.