Can You Freeze Insulin? Technically Yes…But Then It’s Ruined & Unusable!
Never Freeze Your Insulin! That Said—Keeping Insulin At “Safe Temperatures” Is Complicated
I learned the hard way on a flight over the Atlantic that “keeping insulin at safe temperatures” isn’t as straightforward as I had hoped. The easy answer is that you should never freeze insulin, but understanding the hypers and hypos (get it?) of safe insulin storage and use ranges is a little more complicated.
This article will help you understand all of those insulin temperature range details as well as give you some tips for when insulin temperature emergencies happen. We’ll also look at some really helpful products for keeping your insulin safe, whether at home or when traveling. Good diabetes management starts with understanding all the rules…and there are a lot!
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Disclaimer: Always refer to your specific drug manufacturer's instructions for storage and safe practices. When in doubt, check their website or give them a call!
What Are The Recommended Temperatures To Store Unopened Insulin?
Unopened insulin should always be stored between 36 and 46 degrees Fahrenheit. The Celcius temperature range for unopened insulin is between 2 and 8 degrees Celsius. If kept within those ranges the insulin should remain effective until the expiration date that’s stamped on the insulin vial or insulin flexpen.
Extreme cold or heat can reduce insulin potency (making it less effective at controlling glucose levels in the body) or completely spoil the insulin, making it unusable and potentially dangerous.
This refrigerated insulin cooler—with optional biogel inserts—is what I now use for transporting insulin, whether during road trips or when traveling internationally for months at a time. Check updated insulin cooler price here.
What Do Frozen Insulin Pens Look Like?
I learned the hard way on a flight over the Atlantic that “keeping insulin at safe temperatures” isn’t as straightforward as I had hoped. The easy answer is that you should never freeze insulin, but understanding the hypers and hypos (get it?) of safe insulin storage and use ranges is a little more complicated.
When my Tresiba basal insulin pens froze while on a plane to Portugal, they essentially expanded and turned into an off-white ooze-bubble at the end of the pen! Into the trash they went. Ouch. Read more about that here.
What Are The Recommended Temperatures To Store Opened Or In-Use Insulin?
Opened or in-use insulin should be stored in the fridge between 36°-46° Fareinheit or 2°-8° Celcius, but can also be kept at “room temperature” which is obviously a little ambiguous. Many insulin producers target temperatures around 85° for the high temperatures safe to keep in-use insulin.
Per Novolog insulin highlights of prescribing information: Opened NovoLog® vials can be stored in the refrigerator at 36°F to 46°F (2°C to 8°C) or at room temperature below 86°F (30°C).
At What Temperature Does Insulin Freeze?
The freezing point of insulin is at 32°F (0°C), just like water. So you can use the rule of thumb that if it freezes your water, it will freeze your insulin. Throw frozen insulin away as it’s no longer safe to use.
What Should I Do If My Insulin Freezes? Can Thawed Insulin Still Be Used?
Nearly every manufacturer of liquid insulin states that once insulin is frozen, it is unusable and should be discarded.
Per Humalog insulin highlights of prescribing information: Do not use HUMALOG® if it has been frozen.
Per Novolog insulin highlights of prescribing information: Do not freeze NOVOLOG® and do not use NOVOLOG® if it has been frozen.
What Happens When Insulin Freezes (The Nerdy Answer)
When insulin is exposed to freezing temperatures, “the solution becomes crystals and these crystals break the protein of insulin completely. So if insulin is frozen, it completely and totally loses its effectiveness.” (Zayani, 2017)
How Long Is Open Insulin Usable, Unrefrigerated Or Kept At Room Temperature?
Depending on the insulin and how it’s being used, most manufacturers direct patients to discard insulin after 28 days, but potentially sooner. Some insulin producers have different discard date ranges based on whether the insulin is used in flexpens or in an insulin pump—which honestly seems a bit odd.
Per Novolog insulin highlights of prescribing information: After vials have been opened: Throw away all opened NovoLog® vials after 28 days, even if they still have insulin left in them. If using NovoLog® in a pump, throw away all opened NovoLog® vials after 19 days.
Of course, any insulin older than the expiration date printed on the insulin should be discarded regardless of whether it’s been/being kept at refrigerated temperatures.
What Is Too Hot Or Too Cold For Insulin—A Visual
Insulin is a very temperature-sensitive medication, which means that it must be kept within specific temperatures in order to remain effective. Too hot or too cold, extreme temperatures can have severe implications on the effectiveness of insulin and may even render it completely ineffective or even dangerous.
The consensus temperature range for in-use, unrefrigerated insulin (per most insulin producers) is between 36°-86°F; 2°-30°C. If insulin is exposed to temperatures outside this range, the medication may become unstable. Temperatures above 86°F (30°C) could cause irreparable damage and reduce insulin efficacy, which will severely impact your diabetes management to say the least!
Good luck getting your blood sugar levels down if your insulin literally stops working because it’s been exposed to high temperatures.
These reusable insulin-cooling wallets are good for when you have to take insulin pens with you outside on long hot days.
FAQS: Frequently Asked Questions About Safe Insulin Storage Temperatures
How Do I Know If My Refrigerator Is Too Cold To Store My Insulin?
Pharmacy refrigerators are specifically built for keeping within temperature ranges and are regularly maintained, but your refrigerator at home is not. And different zones in your fridge can be subtly different temperatures, and even drop to below-freezing temperatures from time to time.
It’s unlikely that you’ll be running out to purchase a pharmacy-grade, climate-controlled refrigerator. Here’s an insulin storage tip: You may want to add one of these small digital thermometers to multiple zones in your fridge, especially the spot where you’re storing your insulin.
What If The Power Goes Out? How Can I Keep My Insulin Safe?
This is where having backup plans comes in really helpful. Consider keeping biogel insulin cooler inserts in the freezer and ready when this emergency happens. Additionally, having a USB-powered refrigerated insulin cooler like this one along with multiple, charged high-capacity power banks should be enough to ensure you can keep your insulin at refrigerated temperatures for at least a couple of days until the power outage is fixed and power it turned back on to your refrigerator.
Final Thoughs On Keeping Insulin At Safe Temperatures
Now you at least know the general rules of safety and temperatures with insulin. You should definitely consider having either a 72-hour biogel insulin cooler on hand or a refrigerated insulin cooler for keeping insulin at refrigerated temperatures. And you should minimally have some insulin cooling wallets like these if you’re traveling with insulin during hot summer months.
Reference:
Zayani, A. (2017, July 29). Part 2, Refrigerators: The Friend-Enemy of Insulin. https://www.diabetesincontrol.com/amin-zayani-part-2-refrigerators-the-friend-enemy-of-insulin/
