What's the Best Way to Store Insulin?

Room Temperature or Refrigeration for Your Insulin

insulin and syringe
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The best way to store insulin depends on when you intend to use it. You often buy more than one bottle at a time, and how you store it will depend on when you are going to use it and where you keep it. Here are the rules of thumb and how to store insulin safely.

Store the Insulin You're Currently Using at Room Temperature

The insulin you are currently using on a daily basis should be kept at room temperature.

Not only is room temperature insulin more comfortable to inject, but it remains stable and potent for at least 28 days unless it is exposed to temperatures that exceed 86 F or 30 C or temperatures that go below 36 F or 2C. If you anticipate room temperatures to be outside that range, it’s best to keep the insulin in the refrigerator.

Beware of Room Temperature Risks for Insulin Storage

But be aware of where you are keeping your insulin, because room temperature may be different in different areas of your "room."

  • Keep your insulin out of direct sunlight. Shield it in an area where it won't get sun through a window, whether it is open or closed.
  • Don't keep your insulin next to a heater or heating vent as that area may reach the temperature danger zone.
  • Your car is a hazard area for "room temperature." It can get too cold in winter weather and freeze your insulin. On a sunny day, even in cool weather, a car can heat up to above the danger zone. Never store your insulin in your glove compartment or anywhere in your car.

    Store Insulin for Future Use in the Refrigerator

    Insulin intended for future use should be kept in a refrigerator at a temperature between 36 to 46 F (2.2 - 7.8C). This includes any unused prefilled pens and insulin cartridges. But you do not want to store it any colder or the insulin will freeze and become unusable.

    Do Not Allow Insulin to Freeze

    Frozen insulin is not usable. Be sure your refrigerator is not set too cold and could freeze liquids. If you see ice forming on anything else in your refrigerator, set the temperature a little higher and make sure it isn't freezing.

    Check Your Insulin Before Each Use

    Each time you use your insulin, check the bottle to see if it looks normal. Regular insulin should not have particles or be discolored. NPH or lente insulin should be checked for frosting or crystals on the inside of the bottle, as well as clumps. Don't use insulin that looks suspicious.

    Tips on Insulin Storage

    • Write the start date of your insulin on the label along with the end date (28 days later) when the insulin should be discarded. Insulin manufacturers do not recommend extending the supply beyond this point.
    • Always have an additional supply of insulin on hand in the refrigerator in case your current supply loses potency, is damaged or lost.
    • Check the insulin package insert or talk with your pharmacist about specific storage information that may pertain to the type of insulin you are using.


      Handling and Storing Insulin. LillyDiabetes. Accessed January 8, 2009.

      Insulin Storage and Syringe Safety. American Diabetes Association. April 7, 2014. Accessed February 11, 2016.

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