Key takeaways:
Most insulin manufacturers recommend storing unopened insulin in the fridge. But many insulin products can be unrefrigerated for up to 28 days. There are a few exceptions.
Avoid exposing your insulin to extreme hot or cold temperatures.
Always read the manufacturer’s instructions for storing your particular type of insulin.
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If you have diabetes and use insulin to control your blood glucose (sugar), you may have noticed that the pharmacy keeps it in the fridge before you pick it up. But should you also keep it in your fridge at home? What about once you open it?
Storing your insulin correctly can be tricky, especially if you use more than one type. Continue reading for more information on how best to store your insulin.
Does insulin need to be refrigerated?
The short answer: Yes. Most manufacturers recommend refrigerating unopened insulin.
Why is that? Insulin is a peptide hormone. Peptide hormones can spoil if not stored properly. All insulins are best kept in the fridge to keep them from spoiling before their expiration date.
What are the general storage recommendations for insulin?
Most insulin manufacturers recommend storing your unused insulin vial or pen in the fridge at temperatures between 36°F and 46°F.
With this recommendation in mind, there are some key things to consider when storing insulin:
Avoid freezing: Don’t freeze your insulin or place it near the cooling element in the fridge (the part of the fridge that makes it stay cold). If your insulin freezes, you shouldn’t use it — even after it’s thawed. Once it’s been frozen, insulin may not work as well.
Avoid extreme heat: Store your insulin away from heat and light. Exposure to heat and light can cause insulin to break down, which means it may not work as well. Don’t store your insulin in your car or in warm areas of your house, such as near the stove.
Check insulin before use: Always check your insulin when you first get it and every time before you use it. If your insulin doesn’t look like it normally does, it’s best not to use it. Changes in color, cloudiness, or floating particles could be signs that it wasn’t stored correctly.
Travel storage: When traveling with insulin, think ahead about how much supply you’ll need and the best way to pack it.
Insulin switching: Some people use more than one type of insulin or may switch insulin types due to changes in treatment or an emergency. Be sure to store each type of insulin according to its specific storage requirements.
What happens if insulin isn’t refrigerated?
When unopened insulin isn’t refrigerated, it may not last until the expiration date printed on the package. Most insulins last about 1 month when stored at a controlled room temperature. Beyond this date, insulin can start to break down and become less effective.
If insulin isn’t stored correctly, it can spoil and not work as well. Insulin keeps your blood sugar levels from getting too high. So if your insulin isn’t effective, you could experience hyperglycemia (high blood sugar). Early hyperglycemia symptoms can include feeling thirsty, urinating frequently, and having blurry vision. More serious symptoms can include confusion, weakness, and shortness of breath.
How can I tell if my insulin is spoiled?
Always check the color and consistency of your insulin before you use it. If your insulin is spoiled, it might look different than it normally does. For example, if it’s usually clear but is now cloudy, it may be spoiled.
But it's not always so obvious. Spoiled insulin may look the same as unspoiled insulin. You may not know you have spoiled insulin until your blood sugar readings start to change without explanation. That’s why it’s important to know how to store your insulin.
Keep in mind: Some insulin products such as Humulin N are cloudy instead of clear. It’s important to know what type of insulin you have and what it normally looks like. That way if anything changes in how it looks, you’ll know it may be best not to use.
Can I use my insulin right out of the fridge?
Yes, you can use your insulin right out of the fridge. But injecting cold insulin may be uncomfortable and cause local irritation.
Before opening a new insulin vial or pen, you can remove it from the fridge and let it reach room temperature before injecting it. This should help avoid the discomfort from injecting cold insulin.
After the first use of your vial or pen, follow the manufacturer’s instructions for how long you can store your insulin at room temperature. This depends on the type you use.
Can you put room temperature insulin back in the fridge?
No, insulin that has come to room temperature shouldn’t be put back in the fridge. Once insulin reaches room temperature — even if it’s unopened — the clock starts ticking on how long it will last. The amount of time your insulin will last at room temperature depends on the specific product you have.
How long can you store insulin outside of the fridge?
Different forms of insulin, and even different brands, may have different storage instructions. Below, we’ll discuss how different forms of insulin are stored. Always read the instructions on your insulin box and ask your pharmacist for specific storage directions.
For reference, refrigerated temperature is 36°F to 46°F and room temperature is 59°F to 77°F or 86°F (depending on the product).
Insulin vials
Unopened insulin vials can be stored in the fridge until their expiration date and outside the fridge for 28 days. Once opened, most insulin vials last up to 28 days inside or outside the fridge. These include:
Insulin glargine (Lantus)
Insulin lispro (Humalog)
Insulin glulisine (Apidra)
Some insulins last longer than 28 days outside the fridge. These are listed below.
Unopened | Opened | ||
|---|---|---|---|
Room Temperature | Refrigerated | Room Temperature | |
Human insulin (Humulin N) | 31 days | 31 days | 31 days |
Insulin degludec (Tresiba) | 56 days | 56 days | 56 days |
Insulin in your insulin pump
The length of time you can keep insulin in your pump depends on the insulin you use. As a general rule, if you expose the insulin in your pump to warm temperatures (higher than 98.6°F), you should replace it.
Pump manufacturers may provide different instructions than those on your insulin box, so always check the instructions for your specific pump. If your insulin box and pump instructions differ, follow whichever instructions are stricter (the shortest number of days for changing out insulin). Make sure to also follow your healthcare team’s instructions.
Insulin pens
Unopened insulin pens can be stored in your fridge until their expiration date. Unlike vials, insulin pens shouldn’t be refrigerated once opened.
Most manufacturers recommend keeping your pen outside the fridge and at room temperature once you start using it. When storing an insulin pen, make sure the cap is on to protect it from light and remove the needle to prevent air bubbles and contamination.
And you can keep most insulin pens — opened or unopened — outside the fridge for 28 days, the same length as most vials. These include:
Insulin glargine (Lantus Solostar)
Insulin lispro (Humalog KwikPen)
Insulin glulisine (Apidra Solostar)
Insulin aspart (NovoLog FlexPen; Fiasp FlexTouch)
But there are a few exceptions, shown in the table below.
Unopened | ||
|---|---|---|
Room Temperature | Room Temperature | |
Humulin N KwikPen | 14 days | 14 days |
Insulin glargine 300 units/mL (Toujeo Solostar) | 56 days | |
Insulin degludec (Tresiba FlexTouch) | 56 days | 56 days |
Insulin icodec-abae (Awiqli) | 12 weeks |
Insulin mixes
Different insulins are sometimes combined in the same vial or pen. This is called an insulin mix. Unopened insulin mix vials and pens can be kept in the fridge until their expiration date.
With most vials, you can store them for 28 days in the fridge or at room temperature once they’re opened. This includes vials of insulin lispro 75/25 and 50/50 (Humalog 75/25 and Humalog Mix 50/50) and insulin aspart 70/30 (NovoLog Mix 70/30). An exception is 31 days for Humulin 70/30.
Mixed insulin pens can’t be stored in the fridge if they’re opened. Once opened, different pens have different storage requirements. See below for examples.
What if you need to dilute your insulin?
You may need to dilute your insulin if you’re prescribed a very small dose that’s less than half a unit. Only dilute your insulin with the diluent that comes in the box. Always follow the manufacturer’s instructions on how to dilute it.
After diluting insulin aspart (Novolog), you can keep it at room temperature for 28 days. After diluting insulin lispro (Humalog), you can keep it refrigerated for 28 days or at room temperature up to 86°F for 14 days.
Insulin inhalation powder
Afrezza is an inhaled insulin. It comes as a dry powder in a blister pack, wrapped in foil packaging. It should be stored in its original foil package in the fridge until the expiration date written on the box.
Once the foil package is opened, you can keep the unused blister pack in the fridge for up to a month or at room temperature for up to 10 days. Once the blister pack is opened, you should use whatever is left within 3 days.
Frequently asked questions
In general, empty insulin containers — including vials, pens, and cartridges — can go in the regular household trash as long as there are no needles or syringes attached.
Unused or partially used insulin containers are considered medical waste and should not go in your household trash. Instead, it’s recommended by the FDA to use a drug take-back program to get rid of your unused medication. You can find a disposal program through:
DEA-sponsored local events such as National Drug Take Back Day
Authorized pharmacies
Prepaid envelopes that are available online to mail your medication
Packing your insulin for travel doesn’t have to be complicated. If you’re starting your trip with refrigerated insulin, it’s best to keep it cool. You can consider storing your insulin in a cooler with ice packs or in a travel case specifically designed for insulin. Keep in mind that your insulin should not touch the ice so it doesn’t get too cold.
It’s okay to travel with your insulin at room temperature, too. But take into account how long it will last, according to the manufacturer’s instructions. That way you can plan how much insulin to take for your trip.
In general, empty insulin containers — including vials, pens, and cartridges — can go in the regular household trash as long as there are no needles or syringes attached.
Unused or partially used insulin containers are considered medical waste and should not go in your household trash. Instead, it’s recommended by the FDA to use a drug take-back program to get rid of your unused medication. You can find a disposal program through:
DEA-sponsored local events such as National Drug Take Back Day
Authorized pharmacies
Prepaid envelopes that are available online to mail your medication
Packing your insulin for travel doesn’t have to be complicated. If you’re starting your trip with refrigerated insulin, it’s best to keep it cool. You can consider storing your insulin in a cooler with ice packs or in a travel case specifically designed for insulin. Keep in mind that your insulin should not touch the ice so it doesn’t get too cold.
It’s okay to travel with your insulin at room temperature, too. But take into account how long it will last, according to the manufacturer’s instructions. That way you can plan how much insulin to take for your trip.
The bottom line
Insulin is sensitive to extreme temperatures and light. Storing your insulin correctly ensures that it remains effective. If stored incorrectly, it may spoil and become ineffective.
Different insulins have different storage recommendations, and it can get confusing. Always read the manufacturer’s recommendations to check how to store your insulin. If you have any questions about how to store your insulin, talk to your prescriber or pharmacist.
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References
American Diabetes Association. (n.d.). Insulin storage and syringe safety.
American Diabetes Association. (n.d.). Safe storage of insulin. Diabetes Disaster Response Coalition.
American Diabetes Association. (2022). Switching between insulin products in disaster response settings. Diabetes Disaster Response Coalition.
A-S Medication Solutions. (2023). Novolog- insulin aspart injection, solution [package insert].
A-S Medication Solutions. (2024). Insulin degludec- insulin degludec injection, solution [package insert].
A-S Medication Solutions. (2026). Novolog Mix 70/30- insulin aspart injection, suspension [package insert].
Eli Lilly. (2024). Humulin 70/30, Humulin 70/30 KwikPen - insulin human injection, suspension [package insert].
Eli Lilly. (2025). Humulin N - insulin human injection, suspension [package insert].
Eli Lilly. (2026). Humalog Mix50/50, Humalog Mix50/50 KwikPen- insulin lispro injection, suspension [package insert].
Heinemann, L., et al. (2020). Insulin storage: A critical reappraisal. Journal of Diabetes Science and Technology.
Institute for Safe Medication Practices. (n.d.). Storage of insulin.
Mannkind. (2026). Afrezza- insulin human powder, metered [package insert]; Afrezza- insulin human [package insert].
Novo Nordisk. (2026). Awiqli- insulin icodec-abae injection, solution [package insert]. DailyMed.
Sanofi-Aventis U.S. (2025). Toujeo, Toujeo Max- insulin glargine injection, solution [package insert].
U.S. Drug Enforcement Administration. (n.d.). Take Back Day.
U.S. Food and Drug Administration. (2024). Drug disposal: Dispose "non-flush list" medicine in trash.
U.S. Food and Drug Administration. (2025). Where and how to dispose of unused medicines.
