Key Takeaways:

  1. Insulin is a crucial hormone for regulating blood sugar levels in individuals with diabetes, and its proper storage is essential for optimal effectiveness.
  2. Unopened insulin should be refrigerated, and once opened, it can be kept at room temperature as per the manufacturer’s instructions.
  3. Insulin is sensitive to extreme temperatures, both cold and hot, which can cause it to spoil.
  4. Different types of insulin have specific storage guidelines, so it’s essential to follow them carefully.
  5. Cold insulin can be uncomfortable to inject, so allowing it to reach room temperature can make the process more comfortable.
  6. Unopened insulin vials and pens can generally be kept in the refrigerator until their expiration date.
  7. Leaving insulin at room temperature for too long can lead to bacterial growth, rendering it ineffective.
  8. Using spoiled or frozen insulin can result in high blood sugar levels and related symptoms.
  9. Regularly inspect insulin for any changes in appearance, such as clumps, threads, or a cloudy appearance in the case of NPH insulin.
  10. Proper disposal of syringes and needles is crucial to prevent infections and environmental hazards, so follow local guidelines for sharps waste disposal.

Beginning insulin therapy can be an overwhelming process, with lots of things to remember and consider. This article will walk you through the specifics of insulin storage, which is an important part of achieving maximal efficacy with your regimen.

What is insulin?

Insulin is a natural hormone found within the body. The pancreas produces insulin, helping your body to regulate your blood sugar levels and use sugar as energy. Diabetes disrupts blood sugar levels, either through insufficient insulin production or via insulin resistance. By providing insulin to the body via injections, your blood sugar levels are more controlled. This helps to manage diabetes and prevent complications down the line.

Why is insulin storage important?

Insulin is the backbone of many anti-diabetic therapy regimens. However, proper administration and storage of insulin is essential to achieving adequate safety and efficacy of the medication.

Many people starting insulin for the first time may be overwhelmed with the different types of insulin, how to administer it, and how to properly store it. While these considerations may seem complex at first, you will get used to your insulin regimen with time. Nevertheless, it is important to administer and store your insulin correctly for optimal results

In terms of storage, insulin is a bit trickier than your typical medication. Insulin, in many cases, needs to be refrigerated at controlled temperatures. However, there are exceptions and considerations depending on the type of insulin being used and when exactly you are using it. This article will clarify the proper way to store your insulin.

Does insulin need to be refrigerated?

In general, unopened insulin needs to be refrigerated. Afterward, insulin can be kept at room temperature in accordance with manufacturer instructions.

Why does insulin need to be refrigerated?

Insulin is known as a peptide hormone. Peptide hormones can go bad if they are not maintained at a certain temperature. When it comes to insulin as a peptide hormone, it is very sensitive to extreme temperatures that are either too low or too high. Thus, in general, insulin must be kept in the fridge to avoid spoiling prior to its expiration date.

How exactly should insulin be stored?

Different types of insulin will have different storage instructions. However, in general, unused insulin vials or pens should be kept in the refrigerator at a temperature between 36 and 46 degrees Fahrenheit. Insulin should also be kept away from both light and heat, which can cause insulin breakdown.

How long can I leave insulin in the refrigerator?

Just because your insulin is in the refrigerator does not mean that it is safe and effective to use indefinitely. Insulin can still go bad at the appropriate temperature, too. Typically, unopened insulin vials and pens can be kept in the refrigerator until the expiration date.

How will it feel to receive refrigerated insulin?

You can inject yourself with insulin immediately after taking it out of the fridge. However, doing such with cold insulin can cause discomfort, and it may even be a bit painful. To avoid this, you can take the vial or pen out of the fridge until it reaches room temperature. This can make it a bit more comfortable to administer.

How long can I leave my insulin at room temperature?

How long you can leave your insulin vial or pen at room temperature will depend on a few factors, including the type of insulin, manufacturer, and more. Always read and follow the storage instructions included on your insulin to know the appropriate duration to leave your insulin at room temperature. However, general instructions are included below:

  • Insulin vials. Insulin vials that are either unopened or opened can last as long as 28 days at room temperature, and some may last even longer than that.
  • Insulin pens. Different from insulin vials, you should not refrigerate insulin pens after opening. Most insulin pens can be kept at room temperature for 28 days, however, there are some exceptions. Humulin N Kwikpen can only be left out for 14 days, and Toujeo Solostar should not be kept at room temperature at all.
  • Insulin pumps. How long you keep your insulin in the insulin pump will depend on the type of insulin. However, in general, insulin should be replaced if exposed to temperatures greater than 98 degrees Fahrenheit. Be sure to double-check the specific instructions for your pump and insulin.

This table also provides a general guideline for storing your insulin, taking into account unopened versus opened vials/pens and room temperature versus refrigeration. As always, follow administration and storage instructions given to you by your provider and as outlined by your insulin manufacturer.

What should I do with frozen insulin?

Even if you put your insulin in the fridge, there is a risk that it still is exposed to extreme temperatures. In particular, avoid keeping your insulin near the fridge’s cooling element. This part of the fridge is what maintains its cool temperature; however, this area may be colder than other parts of the fridge. Leaving your insulin here may cause it to freeze.

You should not use insulin that has frozen for any reason, even if it has melted. After being frozen, the insulin will not be as effective. Therefore, you should dispose of any insulin that has been frozen.

What will happen if my insulin is left out?

When insulin is left out for too long, bacterial growth can happen. While the bacteria may not make you ill, it can make the insulin ineffective, not providing full therapeutic benefits and therefore not inducing adequate blood sugar control. If you were to leave insulin out for too long, you may have high blood sugars despite taking the right dose at the right time.

What will happen if my insulin is ineffective?

If you use insulin that has spoiled or been frozen, it will not work as well. In particular, you will likely experience hyperglycemia, known as high blood sugar. Signs of high blood sugar include feelings of thirst, blurry vision, frequent urination, drowsiness, weakness, confusion, and shortness of breath.

How do I know if my insulin has gone bad?

It is good to get into the habit of checking the appearance of your insulin every time you use it. Doing so can help you to avoid administering spoiled insulin and receiving an ineffective dose. Before taking insulin, gently roll your insulin to mix it up. Do not shake it, as shaking the vial can alter the appearance of the insulin and impact its efficacy. Then, inspect it for the following:

  • Clear color, except if you use NPH insulin. NPH insulin is the only type of insulin that should appear consistently cloudy after rolling it.
  • Free from clumps or threads. If you notice either of these, the insulin may have gone bad.

Can I reuse syringes?

Some people want to reuse their syringes as it is more affordable, decrease waste and prevents the need to buy syringes in bulk. However, sometimes reusing syringes may be unsafe, as they are no longer sterile after first use. For example, if you are prone to infection, have open hand wounds, or are sick, reusing insulin syringes increases your risk for infection.

How do I dispose of my syringes and needles?

When considering how to store insulin, it is also important to know how to correctly dispose of your equipment. The best way to do this is by utilizing a needle-clipping device, which can destroy the syringe. However, if you don’t have this, make sure to always cap your needles.

From there put your needles and syringes in a proper sharp disposal container. These can be found online, at pharmacies, or medical supplies companies. Sometimes these can even be covered by insurance. If you do not have a sharps container, use a heavy-duty plastic container with a screw top. Ensure you visibly label it “sharps waste” to alert others of what is inside. Never dispose of your syringes in the trash or recycle bin.

Utilize your local community guidelines to know where to get rid of your sharps waste and sharps waste containers.


In summary, insulin storage is an essential part of receiving effective antidiabetic therapy and maintaining your blood sugar levels. In general, insulin should be kept in the refrigerator at controlled temperatures before first use. After first use, insulin vials can be kept at room temperature or in the refrigerator, while insulin pens must be kept at room temperature. Before using insulin, it is important to inspect it for spoiling. Using insulin that has gone bad can be ineffective, resulting in high blood sugar levels and negative long-term effects.