Quick Answer: Frozen insulin loses its effectiveness and is not safe to use. If insulin has been accidentally frozen, it should be discarded to avoid the risk of inadequate blood sugar control.
In India’s hot climate, much of the conversation around insulin storage focuses on preventing heat damage.
But what often gets overlooked is the danger of insulin freezing, especially during winter months in northern regions, or while traveling to hill stations like Shimla, Manali, or Ooty.
Insulin is a temperature-sensitive medicine that must be protected from both heat and cold extremes. Just as it loses effectiveness when exposed to high temperatures, insulin can become ineffective and unsafe if frozen.
In this article, we answer key questions relevant for people across India who rely on insulin for managing type 1 or type 2 diabetes:
🧊 Can you freeze insulin?
❄️ What happens if insulin gets too cold?
🔍 How can you tell if your insulin has frozen?
⚠️ Is thawed insulin still safe to use?
🌡️ At what temperature does insulin typically freeze?
🧳 How can you prevent insulin from freezing during travel?
Understanding these topics is crucial for diabetes management, whether you live in Delhi’s cold winters, use public transport, store insulin at home, or travel across India with your medicine.
With proper knowledge and simple precautions, you can make sure your insulin stays effective and your health stays protected.
Related article: Does Insulin Really Need to Be Refrigerated and How to Store it Properly?
Can You Freeze Insulin?
Despite lingering questions, the consensus is clear: insulin can't be frozen. Across the board-doctors, drug manufacturers, pharmacists, and those with diabetes are unanimous. once insulin has frozen, its efficacy and safety are compromised, rendering it unusable.
What happens if insulin freezes?
Questions about the stability of insulin at freezing temperatures are common, as such conditions can severely impact its integrity and effectiveness.
Amin Zayani, an engineer and advocate for those with Type 1 diabetes, emphasises the importance of managing the storage temperature of insulin. He refers to the fridge as an "insulin frenemy," highlighting how excessive cold, much like heat, can adversely affect insulin.
Freezing causes insulin molecules to crystallize, a permanent change that destroys their biological function, leading to loss of potency and potential health risks.
Related article: How to Keep Insulin Cool While Travelling?
Watch our video on the topic!
At what temperature does insulin freeze?
Insulin's freezing point is the same temperature as water, 0°C. To avoid any risk of accidentally freezing your insulin, it is advised to maintain a buffer and store insulin above 2°C.
Freezing can occur rapidly, potentially within a few hours, so care should be taken to never store insulin at or below its freezing point.
Can You Still Use Insulin if it Has Been Frozen?
No, once insulin has been frozen, it is no longer safe or effective for use. Even if it has only been frozen for a short period and subsequently thawed, using it can seriously impact your blood sugar management, posing significant health risks.
It's important to delve into the guidance provided by the manufacturers themselves, as they are unequivocal in their advice against using insulin that has frozen.
"Do not use NovoLog if it has frozen" Novo Nordisk, the maker of NovoLog, a fast-acting insulin aspart, strictly advises against freezing NovoLog. It should be stored in a refrigerator maintained between 2° and 8°C. It must not be placed in a freezer or right next to the cooling element of the refrigerator.
"Do not allow Lantus to freeze" Sanofi, the manufacturer of Lantus insulin glargine, a long-acting insulin, also warns against freezing. Lantus should never be placed in a freezer or near a freezer pack. If any frost or ice crystals appear in the Lantus solution, it must be discarded.
"Do not use Humulin if it has frozen" Eli Lilly, the producer of Humulin, an isophane intermediate-acting insulin, advises the same care for its vials and pens. Humulin R U-500 should not be used if it has been frozen.
This guidance against freezing insulin is consistent across all insulin types and brands, including Apidra, Humalog, NovoRapid, Tresiba, Levemir, and Toujeo, among others. All insulin manufacturers consistently emphasise the importance of not using insulin that has frozen.
Related article: Can you Use Insulin That Has Been Left Outside the Fridge?
What About Thawed Insulin?
Is thawed insulin still safe to use? Absolutely, not. Once insulin has been frozen and then returns to a liquid state, it must not be used under any circumstances.
Freezing temperatures permanently alter the insulin's effectiveness, making it unreliable for managing blood sugar levels, even after it has thawed.
The risks associated with using thawed insulin are significant. Freezing damages the insulin's structure, impairing its ability to regulate blood glucose properly.
The use of thawed insulin could lead to dangerously unpredictable blood sugar levels. A notable case reported by Postgraduate Medicine Journal highlights the severe consequences: a patient who tried to defrost frozen insulin using a microwave ended up in emergency care due to complete loss of blood sugar control. This case stresses the importance of discarding any insulin that has been frozen to avoid serious health risks.
Related article: Insulin Storage: 10 Common Mistakes to Avoid When Storing Your Insulin Pens and Vials.
How To Tell if Insulin Has Frozen?
If you're uncertain whether your insulin has been accidentally frozen, there are several signs to help you.
Frozen insulin usually appears more solid and opaque, similar to the way water looks when it freezes, indicating that it's no longer viable. When insulin is frozen, it won't inject properly as it cannot pass through the needle.
It's trickier to detect if insulin has thawed after freezing. Once it returns to liquid form, check for any changes in color or texture. Insulin that has been compromised may appear cloudy, form clumps, or contain white particles.
It's important to remember, though, that some types of insulin are naturally cloudy, so know the normal look of the insulin you use.
Additionally, an unusual increase in blood sugar levels can be a secondary indication that your insulin has been affected by excessively cold temperatures.
In any case of doubt, it's safer to discard the questionable insulin. Replace it with a fresh vial or pen from your refrigerator to ensure you are using insulin that will effectively manage your blood sugar levels without risks.
Related article: Can you Inject Cold Insulin Straight From the Fridge?
How to Make Sure Your Insulin Never Freezes
It might surprise you how easily insulin can accidentally freeze, potentially during a power cut in the depths of winter, or perhaps if left in the car overnight. Whether you're navigating colder climates or it inadvertently ends up next to an ice pack in your cooler bag, numerous situations can lead to insulin freezing.
Here's how you can protect your insulin from cold temperatures:
Never store insulin in or near the freezer
Ordinary home fridges often don't provide as stable temperatures as those in medical-grade fridges, especially near the freezer compartment or the drawers - the coldest spots.
When your insulin is stored in the fridge, it's best to store it on the middle shelf, where it's less likely to be exposed to freezing temperatures. Never keep insulin in the freezer.
Related article: Tips for Packing Your Insulin and Needles for Travel!
Use your body heat to protect insulin in cold weather
Travelling or residing in a frosty area? One of the easiest way to stop your insulin from freezing when outdoor is to utilise your own body heat. Keep insulin pens or vials in the pockets of your inner jacket, or even directly against your skin under your clothing for additional warmth.
For insulin pump users, be aware that the insulin in the tubing and reservoir is also at risk of freezing. Devices often come with built-in temperature sensors that alert you if the device becomes excessively cold, aiding in the prevention of insulin freezing.
Only use insulin coolers with anti-freeze protection
When the temperature climbs above 25°C, carrying your insulin in a cooling case is crucial to shield it from the heat. Nonetheless, DIY cooling bags with ice packs often risk freezing your insulin when in direct contact with the ice.
Opt for a cooler with integrated anti-freeze protection, like those offered by 4AllFamily, now available in India, featuring special crystals that freeze at 2°C, slightly above insulin's freezing point, guaranteeing your insulin remains just above freezing even when in direct contact with the cooling element.
Investing in a trustworthy insulin travel cooler with these capabilities is crucial for maintaining your insulin's effectiveness, offering peace of mind whether you're at home or travelling, no matter the season.
We'd Love to Hear from You!
Have you had experiences with frozen insulin? Share your stories and suggestions! What methods have you found effective, and what guidance would you provide to others facing similar challenges? Let's build a supportive community where we can share knowledge and support each other!