How to Safely Store Insulin

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Insulin is a medication that needs to be kept at the proper temperature. If it freezes or gets too hot, it can break down and no longer help you control your blood sugar level. This could hurt not only your health but your wallet, since the cost of insulin has risen dramatically in recent years.

Read on to learn why proper storage is essential and get tips for preventing your insulin from becoming damaged.

Insulin bottle and syringe
Leland Bobbe / The Image Bank / Getty Images

Unopened Insulin

Unopened insulin vials, pens, and cartridges should be kept in a refrigerator at a temperature between 36 to 46 degrees F.

The back of a refrigerator, where the cooling elements are located, tends to be colder and can even cause items to freeze. You may want to use a thermometer to test different spots within your refrigerator. Many people with diabetes find that the butter holder or dairy drawer works best for storing their insulin.

Check the manufacturer's expiration date on the box to see how long your unopened insulin can be stored in your refrigerator. It's usually about a year from when it is purchased.

Opened Insulin

Once opened, insulin vials and cartridges have different storage needs. It's important to read and follow the manufacturer's storage instructions. If you're unsure, ask your pharmacist.

All opened insulin needs to be stored between 36 and 86 degrees F.

Vials: Glass vials are considered open when you stick a needle into the rubber stopper. Open vials can be stored at either room temperature or in a refrigerator for up to 28 days.

If you choose to store your vial in the refrigerator, allow your insulin to warm up before injecting it. This will make your shots less painful.

Cartridges Used in Pens: Opened liquid cartridges should be stored at room temperature, not in a refrigerator. They are good for between seven to 28 days, depending on the manufacturer's instructions.

Opened powdered insulin cartridges need to be used within 10 days. They are sold in blocks of three. An opened block needs to be used within three days.

Other Storage Tips

  • If you're traveling, use an insulated bag to keep insulin at the recommended temperature.
  • Keep your insulin away from any heating or cooling source.
  • Store it away from windows. Sunlight can break down insulin.
  • Never store your insulin in your car or glove compartment. Cars can freeze or heat up quickly.
  • Use a permanent marker to label when you opened your vial or cartridge and when you need to throw it away. This can help ensure you use it before it expires.
  • Monitor your supply constantly. Vials contain 1000 units. If you use more than 35 units a day, you'll run out within a month. Pens have 300 units. If you use more than 10 units a day, you'll run out within a month.
  • Always keep an additional supply of insulin in the refrigerator, in case your current supply is damaged or lost.

Check Insulin Before Using It

Because insulin is temperature-sensitive, it can become damaged as it is being transported or delivered. There are things you can do to make sure your insulin was handled properly before you got it.

If you pick up your insulin at a pharmacy, it shouldn't be sitting out. The pharmacist should have to go to a fridge to get it for you.

Mail order insulin should arrive sealed in a temperature-controlled box. Insulin can become spoiled if it is delivered on a very cold or hot day and left outside for a while. You may want to talk to your mail carrier about this. Use either an app or text messaging to track your deliveries.

If you suspect your insulin was damaged during delivery, don't use it. Always inspect your insulin before you inject it. If you see white clumps, particles, or crystals, or if your insulin has become cloudy or is a different color, don't use it.

Protecting Your Insulin Vials

Getting insulin requires seeing a doctor and getting a prescription. And then there's the actual cost, which has increased rapidly over the past few years.

Depending on your insurance coverage, one vial can cost as much as $300. Many people with diabetes require more than one shot a day, which means more than one vial a month.

Given the high cost, you may want to consider investing in an insulin vial protector. These silicone covers wrap around glass insulin vials and protect them from shattering if you accidentally drop them. They cost between $6 and $9 apiece.


Insulin can be damaged and become ineffective if it isn't stored correctly. This can hurt your health and be a very costly mistake, since the price of insulin is steep. That's why you should always follow the manufacturer's storage instructions.

Unopened insulin should be kept in the refrigerator. Opened insulin needs to be stored at the recommended temperatures and kept out of the sunlight. You also have to be mindful of expiration dates.

A Word From Verywell

Your insulin is vital to controlling your blood sugar levels. Unlike other drugs, you can't just put it in the medicine cabinet.

Living with diabetes isn't easy. Following these storage tips can help prevent your insulin from becoming damaged and ineffective, so it can continue to keep you healthy and safe.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Gary Gilles
Gary Gilles is a licensed clinical professional counselor (LCPC) who has written about type 1 diabetes and served as a diabetes counselor. He began writing about diabetes after his son's diagnosis as an infant.