The Great Frozen Insulin Experiment....part 2

I recall reading somewhere that insulin (or at least some types of such) breaks down around 150~180 degrees.

This was from a protein point of view and was not addressing whether the insulin was or was not effective at or after those temps.

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Yeah, that makes sense, proteins will unwind at some point, and honestly 150 seems unlikely for insulin to reach in the “real” world.

Freezing was because, well it is not inconceivable for insulin to be exposed to freezing temps. If we do this, I am thinking maybe up to 120. That seems to be a reasonable temp that could be reached in a car in the summer.

Maybe 120 for one hour, two hours, etc.

I am also interested to see what temps it takes to make Humalog cloudy.

As a note, I am not sure if there is data on the fact that it always get cloudy when bad.

I think it may get cloudy when it is bad. I am guessing, but I think it is possible for insulin to go bad without becoming cloudy. In fact, I think it happened to us once.

Perhaps it would be possible to gain the interest of a professor on a campus that has access to some UV Spectroscopy equipment?

On other matters we have contacted a couple of research professors and if it is pretty close to their field of research, they seem to get excited pretty fast.

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I think @Eric has some insulin in his freezer he needs to do another experiment with. I’ve got a calendar note that is reminding me to remind @Eric to check his freezer.

Also, thanks @Carol for your frozen insulin post. I was literally standing at the check in desk of a hotel when the front desk guy told me his partner uses insulin and he has lots of hotel guests request a fridge for insulin. I told him I’ve had bad luck with the hotel fridges freezing all my food, and we’ve had success with leaving insulin at room temperature for long stretches. So I busted out my phone to show him FUD and this frozen insulin post was on top! So even if the insulin freezes in a hotel fridge, all is not lost. :wink:

Glad FUD was an encouragement to you! It certainly has been helpful for us.

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I am an undergrad researcher in a biology lab right now. I’ll have to check if our lab has a UV spec. I don’t think so but maybe I just haven’t noticed because I haven’t needed it. This really wouldn’t be related to our research but maybe they’d let me do a bit of a personal experiment haha.

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@Chris: My husband wasn’t able to add any helpful information. He’s been my objective help as I’ve tried to fit my eating habits to match the movement of the frozen Humalog. We both appreciated your hard work.

@Michel: Glad my story could be helpful. :slight_smile:

I’ve been carefully using expired insulin for several years, and someone recently sent me this article. Someone else may find it interesting - or maybe you’ve already seen it.

Integrated Diabetes Services (IDS) provides detailed advice and coaching on diabetes management from certified diabetes educators and dieticians. Insulin Nation hosts a regular Q&A column from IDS that answers questions submitted from the Type 1 diabetes community.

Q: Should I really worry about using insulin after its expiration date? What about using it for more than 30 days? I think the insulin companies promote that just to make us throw out good insulin.

A: When it comes to insulin…

The insulin manufacturers are required to test their products rigorously before bringing them to market. They can more or less guarantee that their products will work as indicated if used within the expiration date and for not more than a month after the seal on the vial, cartridge, or pen is broken. This is, of course, assuming that the insulin has been stored properly and not exposed to extreme heat, freezing cold, or direct sunlight.

Does this mean that insulin suddenly goes belly up at the stroke of midnight on the expiration date, or 28 days after being put into use? Hardly. Many people, including clinicians with diabetes, have used insulin beyond the “deadlines” without a hitch. It simply means that the manufacturer has not tested their product beyond the dates indicated, so there is no guarantee — no way of knowing exactly how long the insulin will remain at full strength.

This is where common sense comes into play. For those with good insurance coverage and plenty of insulin on-hand, it’s best to follow the rules and discard insulin that is past its expiration date or intended length of use. It just isn’t worth the risk.

However, if you have high out-of-pocket costs for insulin, or your supplies are limited, it may be worth stretching the life of your insulin a little bit. Just be on the lookout for anything out of the ordinary, such as higher-than-expected glucose levels, discoloration of the insulin, or unusual skin reactions. Any of these means that you need to switch to fresh insulin right away.

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@TravelingOn: Glad the timing worked for you! :slight_smile:

Thanks for the additional information Carol, in case you haven’t seen it, here is @Eric 's expired insulin test.

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Oh, I wish you had posted this about a month ago. I would have run the experiment because I would have guessed that it can get well over 120 in the car in summer. These guys say 140: Estimated Vehicle Interior Air Temperature v. Elapsed Time and these guys say 172: NameBright - Coming Soon but I’m really not sure how much to trust those numbers.

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Yeah. I would not use it at 172. Clearly at a certain point the protein has to break down. From my reading, it depends on the structure of the protein as well as what else may be mixed in with the insulin.

From a theoretical point it is extremely interesting and would be fun to scientifically test different temps with various forms of insulin. As I understand, a UV Spectroscope can be used to show at what point the protein actually begins to degrade (temperature-induced denaturation).

From a practical point of view, I would not use insulin that I reasonably thought was exposed to temps at or above 140.

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I forgot to come back and mention that my lab does have a spectrophotomer but it might be non-functioning or broken because my lab mates and I could not get it to turn on.

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I use Novorapid 100U/ml and It was stored at cca. -1 Celsius for 24 hours. Visually it is not frozen,the fluid itself is not cloudy but totally clear. It is very strange that I experienced several extraordinary low BG values just after injecting the regular dose. It seems that this type if insulin has stronger effect than it had before the freezing.

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@Daniel, that doesn’t surprise me. What we have seen is that the freezing doesn’t destroy the insulin, but that the action curve is changed slightly. In the case of Humalog we felt it covered the same amount of carbs, but the way it acted was different.

Do you feel that the Novorapid still covered the same amount of carbs, or that it was now more potent?

Interesting finding. Thanks for posting!

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Great to find this about frozen insulin
I am T2 on insulin

My novorapid accidentally got pushed to the back of my fridge and I found it covered in ice. It had been there about 3 months

The vials had hairline cracks
I loaded the vial into the pen and quite a lot of insulin leaked
I used it for one dose and threw the cartridge away as I could not be sure that it was giving accurate units

The next cartridge I ensured that the plunger was fully pushed up.
This time the vial didn’t crack and I was able to use all the insulin

I did notice the delayed curve of action and thanks to this forum I was able to monitor and avoid any lows

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Welcome @JuliaWsM!

I’m glad that reading about it helped!

Sorry to hear about your own unexpected frozen insulin experiment. That’s a bummer!

There’s a few threads on insulin storage on here, but I like this one:

And I like to store ours in the door so it’s a) easy to find, and b) doesn’t roll away. My fridge freezes everything in the back it seems. Did you like frosty lettuce? No? How about half and half with ice?!? :upside_down_face:

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Glad you were able to find some info, yeah a cracked vial sounds bad, fortunately we haven’t seen that, but we haven’t used pens in a few years. Also, thanks on confirming the delayed action curve. Every data point helps complete the picture. Throwing insulin away is a very rare occurrence in our house. It helps that my son is now 16 and can eat a ton, so we actually use a lot of insulin as well.

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Ha! “Here, son. Just have another pizza and this leftover quart of milk. Then we can use the insulin that’s about to expire.” :rofl:

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Hello Folks,

I am Arryo from Indonesia, A T2DM. I am very happy to find this froum, and this thread in particular, after being freaked kut this monrning discovering my Lantus converted to Iced-Lantus.

Thanks to internet that helped me reading all your experiences on mistakenly frozen insulin.
I am pretty sure that I can learn a lot fron this forum…
Once again, thank you for lettimg me join the forum.

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Glad to have you here, and happy that you found some content to connect with. I haven’t actually frozen our Lantus before, so if you can contribute how it works (my guess is same as unfrozen) that would really help our knowledge base.

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