Managing insulin storage correctly can be tricky for people with diabetes, even though it's essential for keeping blood sugar levels in check. If insulin isn’t stored at the right temperature, it can lose effectiveness, which may lead to poorly controlled blood sugar and serious diabetes-related health complications.
Generally, insulin should be refrigerated between 2°C and 8°C before use. Once opened, it can be stored at room temperature, but only if it stays below 25°C, and even then, only for up to a month.
However, there’s more to insulin storage than these general rules. Below, we’ve put together a comprehensive guide to help answer your most pressing questions about insulin storage, refrigeration, and temperature control:
- When does insulin have to be refrigerated and when can it be kept at room temperature?
- What happens if insulin gets warm?
- How long can insulin be out of the refrigerator?
- How long is insulin good for?
- At what temperature does it freeze?
- How to keep your insulin cool when traveling?
- And much more!
Does Insulin Need to Be Refrigerated?
Yes, insulin pens and vials need to be kept in the fridge before you start using them, no matter the type, brand, or packaging. Whether you're using Lantus, Novolog, Humalog, fast-acting insulin, basal insulin, or any other type, it’s essential to store your insulin pens, vials, and cartridges in the refrigerator as soon as you get back from the pharmacy.
The ideal insulin temperature range in the refrigerator is between 2°Celsius and 8°Celsius. Be cautious not to set the temperature too low, as freezing insulin can damage it and make it ineffective.
It’s a good habit to regularly check the temperature of your fridge. Using a smart thermometer can help, as it can notify you if the temperature moves outside the safe range, such as during a power outage for instance.
For a visual explanation, check out this helpful video on insulin storage:
Why Must Insulin Be Refrigerated?
Like other diabetes injectable medications, such as Mounjaro, Ozempic, Trulicity, Victoza, or Byetta, insulin is classified as a biologic. These medications contain ingredients derived from living organisms, making them particularly sensitive to changes in storage temperature and light.
Refrigerating insulin helps maintain its effectiveness and stability before it’s used:
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It preserves insulin's potency. Insulin is a protein that can degrade over time if exposed to heat. By storing it in the fridge at temperatures between 2°C and 8°C, you ensure its molecular structure remains intact, preventing breakdown and ensuring it can effectively manage blood sugar levels.
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It extends insulin’s shelf life. Insulin kept in the refrigerator stays potent until the expiration date indicated on its packaging. Higher temperatures can accelerate the degradation process, expediting insulin expiration.
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It prevents bacterial growth. Warmer temperatures can promote bacterial growth in biologic medications like insulin. Refrigeration helps mitigate this risk, ensuring that your insulin remains safe to use.
While all types of insulin must be refrigerated prior to use, specific storage temperatures and guidelines may differ based on the brand or type of insulin. Always refer to your insulin’s storage instructions!
How long is insulin good for in the fridge?
Unopened insulin stored in the refrigerator will remain usable until the expiration date marked on its packaging. Each insulin pen, vial, or cartridge comes with an expiration date labelled by its manufacturer.
Generally, insulin is good for about one year from the purchase date, when properly stored in the fridge. Be sure to double-check this date, and if you’re uncertain, your pharmacist can help clarify.
Once insulin passes its expiration date, it’s no longer safe to use. Even if it has been continuously stored in the refrigerator and remains sealed, expired insulin should never be used, as it could pose serious health risks.
Where to store insulin in the refrigerator?
Here are some useful tips for storing your insulin in the refrigerator correctly:
- Keep the temperature stable: Make sure your fridge maintains a consistent temperature between 2°C and 8°C, avoiding any sudden changes and temperature fluctuations as much as possible.
- Ensure proper air circulation: Don’t overpack your fridge—allow enough space for air to circulate freely, which helps your fridge function better.
- Limit fridge door openings: Frequent opening of the refrigerator can cause temperature fluctuations, so try to minimize it.
- Avoid freezing insulin: Never store insulin near the freezer section, as freezing will make it ineffective.
- Store insulin in the center of the refrigerator: Store your insulin pens or vials in the middle of the fridge, away from the door and walls where temperatures can fluctuate more.
- Regularly monitor your fridge temperature: Check your fridge temperature often, and consider using a smart thermometer for added precision.
How Long Can Insulin Be Out of the Refrigerator?
Once it's opened, insulin doesn’t need to be refrigerated. After you’ve started using an insulin pen or vial, it can be safely stored at room temperature, as long as it stays below 25°C.
Typically, insulin can be out of the refrigerator for up to a month, though the exact duration can vary depending on the brand and type. For instance:
- Lantus (insulin glargine): up to 28 days.
- Novolog (insulin aspart): up to 28 days.
- Humalog (insulin lispro): up to 28 days.
- Humulin N (insulin NPH): up to 31 days.
- Humulin R (insulin regular): up to 31 days.
- Apidra (insulin glulisine): up to 28 days.
- Novolin N (insulin NPH): up to 42 days.
- Novolin R (insulin regular): up to 42 days.
- Levemir (insulin detemir): up to 42 days.
- Tresiba (insulin degludec): up to 56 days.
- Toujeo (insulin glargine): up to 42 days.
- Fiasp (insulin aspart): up to 28 days.
- NovoRapid (insulin aspart): up to 4 weeks.
Insulin Stability at Room Temperature
As mentioned earlier, insulin needs to be refrigerated before you start using it. However, once opened, insulin is stable at room temperature for about a month. Make sure to keep track of this period and never use insulin that’s been out of refrigeration for too long.
When insulin is not refrigerated, it should be kept at room temperature, away from heat, and protected from direct light. It’s essential that insulin is stored below 25°C at all times. So, if you live in or are traveling to warmer climates where temperatures might exceed 25°C, using an insulin cooler is necessary to keep it cool and preserve its effectiveness.
As mentioned above, insulin needs to be refrigerated before use. But once opened, it's ok to keep it out of the fridge. In that case, it will be good for approximately a month. So, make sure to keep track of this timeframe and never use insulin that's been out of the fridge for too long.
When not refrigerated, insulin must be kept at room temperature, shielded from heat, and protected from light. When not refrigerated, insulin must always be kept below 77°F (25°C). So, if you live in or travel to warmer climates where ambient temperatures may exceed 77°F (25°C), you would have to use an insulin cooler to keep your insulin cool and maintain its effectiveness.
Always refer to the specific storage temperature guidelines that come with your insulin. If you’re unsure about anything, don’t hesitate to consult your healthcare provider or pharmacist to get clarity!
Can You Put Insulin Back In The Fridge?
Yes, in most cases, you can put insulin back in the fridge to preserve its effectiveness. If the room temperature in your home is on the warmer side, placing insulin back in the fridge can be a better option than exposing it to temperatures outside of its safe storage range.
However, keep in mind that putting insulin back in the fridge won’t extend its shelf life. Once an insulin pen, vial, or cartridge has been opened or left at room temperature, it’s only good for about a month—whether you store it at room temperature or back in the fridge!
How to Keep Insulin Cool When Traveling
Traveling with temperature-sensitive injections like insulin requires extra planning, especially if refrigeration is necessary. Here are some handy tips to help keep your insulin cool or refrigerated, depending on the type and length of your travel:
- If you're traveling with insulin that needs to be refrigerated
If your trip lasts longer than a month or you need to transport unopened insulin vials or pens that need to be refrigerated, investing in a mini insulin fridge for travel is key.
Medical-grade insulin refrigerators like the Voyager Mini Fridge for Insulin, the Explorer 3-in-1 Insulin Cooler, or the Nomad Insulin Cooling Cases from 4AllFamily provide reliable cooling solutions. These travel refrigerators maintain fridge-like temperatures, ensuring your insulin stays refrigerated and safe while you're traveling or on the go.
- If you're traveling with insulin that needs to be kept cool at room temperature
For shorter trips (under a month) with insulin that’s already been opened and can be stored at room temperature, a simpler insulin cooler will work just fine.
Products like the Chiller Cool Pouch for Insulin, the Companion Insulin Cooler Bag, or the Rambler Small Insulin Pen Cooler help maintain a safe internal room temperatures range below 25°C, keeping your insulin cool while traveling.
Protect insulin from light and breakage
Direct sunlight and even indoor lighting can weaken insulin and reduce its effectiveness. Always keep your insulin vials and pens in a shaded spot to avoid light exposure.
If you’re using insulin pens, make sure to keep the cap on whenever they’re not in use to further protect the insulin from light.
Insulin vials are often made from delicate glass, which can easily break if dropped. To prevent this, consider using a silicone vial protector. This simple tool can help safeguard your insulin from shattering in case of an accidental fall!
FAQs About Insulin Storage Temperatures & Refrigeration
What happens if insulin left out of the fridge?
When insulin is left unrefrigerated for too long, its potency can diminish, making it less effective at controlling blood sugar levels. It may also spoil, showing signs like clumping or discolouration.
Typically, insulin can stay unrefrigerated for up to a month, though this can vary depending on the brand and formulation. Always follow the manufacturer’s storage guidelines, which usually recommend keeping insulin refrigerated until first use, and then storing it at room temperature (below 25°C) after that.
Does insulin go bad?
Yes, insulin can go bad and spoil if it’s left unrefrigerated for too long or if exposed to temperatures above its safe range.
While insulin is naturally sensitive, most types are formulated to remain stable at room temperature for around a month (below 25°C), though some may last slightly less or a bit longer. If insulin is kept outside of refrigeration for longer than this period, it can start to degrade, reducing its potency and effectiveness.
What if insulin is left out of the fridge for 2 hours?
If your insulin was left out of the fridge for just 2 hours, it is generally still safe to use. Most types of insulin are stable at room temperature (25°C) for up to a month once removed from the fridge.
A brief period out of refrigeration, like 2 hours, should not significantly affect the insulin's efficacy or safety, provided the ambient temperature is not excessively hot. However, it's important to return your insulin to the fridge as soon as possible. Always refer to your specific insulin's storage instructions for precise guidance.
What if insulin is left out of the fridge for 12 hours?
If insulin was left out of the fridge for 12 hours, it is typically considered to have been removed from refrigeration, breaking the cold chain required to maintain its longest shelf life in the fridge. Leaving your insulin out for 12 hours moves it into this usage phase rather than optimal storage.
In that case, it should be used within one month, but this duration can vary depending on the specific type of insulin. Check that your insulin does not show signs of spoilage, such as cloudiness, discolouration, or particles, which could indicate it has gone bad.
Should insulin pens be refrigerated too?
Yes, insulin pens need to be refrigerated too. As mentioned earlier, all types of insulin, no matter the packaging, must be stored in the fridge before use.
Whether you’re using disposable insulin pens, cartridges for reusable injector pens, or insulin vials with syringes, it’s crucial to store them in the refrigerator until you’re ready to use them.
How to store insulin without refrigeration?
- Follow temperature guidelines: Most insulins can be safely stored at room temperature (below 25°C) for around 28-30 days after opening. Always double-check your insulin’s specific storage instructions.
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Keep it cool and dry: Store insulin away from direct sunlight and heat. Ideal locations include a drawer or a cupboard away from heat sources.
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Use within a month: Aim to use the insulin within a month if it's not refrigerated. Make sure to track when you first opened or removed it from the fridge.
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Inspect regularly: Always check your insulin for any signs of discoloration or cloudiness. If it looks unusual, don’t use it.
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Protect from heat: Avoid leaving insulin in hot places like a car or near a stove, as even brief exposure to extreme temperatures can cause it to spoil.
What happens if insulin gets warm?
Insulin is extremely sensitive to high temperatures and can degrade quickly if it gets too warm. Research shows that insulin’s stability drops significantly when exposed to temperatures above 26°C. And, the longer it remains in these conditions, the more its potency declines.
It’s surprisingly easy for insulin to get warm, accidentally. Leaving it in a car on a sunny day, near a stove, or even in a purse on a hot day can expose it to temperature outside of its safe room temperature range. Once insulin has been exposed to high temperatures, even for a short period, it’s no longer considered safe to use.
Using bad insulin can lead to higher blood sugar levels and serious diabetes complications, such as diabetic ketoacidosis. In emergencies, if no other insulin is available, you might need to use warm insulin cautiously. However, it’s highly recommended to replace it with a cold vial or pen from a refrigerator or pharmacy as soon as possible.
Does insulin expire?
Yes, like any medication, insulin expires. Insulin can expire under three main conditions:
- It passes its expiration date.
- It’s been out of the refrigerator for more than a month.
- It’s been exposed to temperatures above 25°C, even for a short time.
In any of these cases, the insulin is considered expired and should not be used.
We’d Love to Hear From You!
We hope this article has made you feel more confident about storing your insulin properly, whether at home or while traveling. If you have any questions, personal experiences, or extra tips about insulin storage and refrigeration, we’d love for you to share them in the comments below. Your insights could make a big difference for others!
