There's nothing more frustrating when you have an insulin-dependent diabetes than losing an entire vial or pen of insulin because it became too warm or was left unrefrigerated for too long.
One key aspect of insulin therapy is understanding insulin's storage requirements and its sensitivity to temperature changes.
Before opening, insulin must be stored in a refrigerator to maintain its potency until first use. Once opened, however, the rules change, and your insulin vials or pens can be kept at room temperature, provided they're protected from excessive heat and light exposure.
This brings us to a common question many insulin users have: Can you put insulin back in the fridge after opening or after it has been at room temperature for a while? Well, let's answer!
Related article: Does Insulin Need to be Refrigerated? Essential Storage Tips!
Can Insulin Be Re-Refrigerated?
Re-refrigerating insulin is somewhat of a controversial practice. Opinions differ, with some experts saying it's acceptable and others advising caution against drastic temperature changes and fluctuations.
Generally though, insulin can be returned to the refrigerator if necessary. Actually, putting your insulin back in the fridge can be particularly helpful if the ambient temperature in your home is too high (above 77°F or 25°C) and you don't have an insulin cooler to maintain it at a safe room temperature range. If you find yourself without an insulin cooler and the room temperature exceeds 77°F (25°C), placing it back in the fridge may be your best option to maintain its efficacy.
However, and that's a very important point to understand, re-refrigerating insulin won't extend its shelf life.
Once an insulin pen, vial, or cartridge has been opened or taken out of the fridge, it typically remains effective for about a month, regardless of whether it is stored at room temperature or refrigerated again.
Related article: Can You Use Insulin That's Been Left Out for 1 Hour or Overnight?
How Long Can Insulin Be Unrefrigerated?
Once removed from refrigeration, insulin can generally be kept at room temperature for up to 28 days.
This duration can vary slightly between different brands and types of insulin, usually between 7 days to 56 days. For instance:
- Lantus, Novolog, Humalog, Apidra, Basaglar, Fiasp, Admelog, NovoRapid, Lyumjev, NovoMix and Semglee can be unrefrigerated for up to 28 days.
- Humulin N, Humulin R and Humulin 70/30 can be unrefrigerated for up to 31 days.
- Levemir, Novolin N, Novolin R, Toujeo, can be unrefrigerated for up to 42 days.
- Tresiba can be unrefrigerated for up to 56 days.
- Novolin 70/30 (premixed insulin): up to 6 weeks.
- Humalog Mix 75/25 (premixed insulin): up to 10 days.
Always check the storage instructions provided with the specific brand and type of insulin you've been prescribed.
Even when insulin is unrefrigerated, temperature control is still crucial. In no case should insulin be exposed to temperatures above 25°C (77°F), even briefly. Higher temperatures can quickly degrade its potency.
Related article: How to Travel With Insulin That Needs Refrigeration or Cooling!
So, Should You Put Your Insulin Back in the Fridge?
The bottom line is that yes, you can return your insulin to the refrigerator if necessary, although it may not always be the best solution.
Below are several general guidelines to help you determine when it's appropriate to re-refrigerate your insulin, how to store it effectively, and what additional factors to consider. Keep in mind, these are broad recommendations and may not apply universally to all types and brands of insulin. Always refer to the specific guidelines provided with the insulin you're using.
- You can keep your insulin refrigerated at all times. If you chose to do so, only take insulin out of the fridge when you're ready to use it. While injecting cold insulin can be slightly more painful, it is as effective as room-temperature insulin.
- Or you can keep your insulin at room temperature once opened. Make sure it's never exposed to direct light or temperatures above 77°F (25°C) and it's used within about a month.
- If necessary, you can re-refrigerate your insulin. If your room temperature is higher than recommended, or you lack an insulin cooler to keep it cool, returning the insulin to the fridge can help maintain its effectiveness. However, remember that this does not extend its shelf life beyond the standard 28 days or the duration specified by the brand.
- Expiration Monitoring: Always check the expiration date on the label of your insulin pen or vial. Regardless of storage method, never use insulin past its expiration date.
Related article: How to Pack Insulin for Travel: Keep it Cool, Safe, and Legal!
Always follow storage guidelines specific to the type of insulin you use, and consult with a healthcare professional or a pharmacist if you have any concerns about your insulin storage or effectiveness.
We'd Love to Hear From You!
Whether you have questions, tips, or personal stories about insulin storage and refrigeration, we're eager to hear from you. Drop us a comment below!
