No concerns in your mind to having 4 mos of insulin packed in luggage continuously without refrigeration? Or only with very sporadic opportunity for refrigeration? Granted I’d probably be able to procure ice along the way… but again… sporadic and the circumstances don’t allow for that being ideal like staying in motels
Granted I don’t expect to be in extreme temps… probably nothing over 80F and even that’d be uncommon… but still…
Not in Alaska, so long as you take care of all the other warnings in this thread (don’t leave it on the parcel shelf on a sunny day). Not in Fiji, or Equador, or Singapore or, for that matter, Kenya either.
The real risk is losing it if you put it all in one piece of luggage. I did that once in London, oops, panic.
I never refrigerated my insulin at all in college. Ever. Most of the time it was in my pocket. And I survived it.
I’d have no hesitation with leaving it unrefrigerated.
Keep in mind, I did not have tresiba. So I can’t speak to that.
But try it out NOW with tresiba. Before you go.
Seems to me Alaska, rappelling, and 3 piece suit don’t seem to mix into a coherent mixture.
Couldn’t agree more
Thanks for sharing this.
My understanding is that insulin is a long-chain protein molecule. I would guess that the warning about temperature sensitivity is based on the denaturing of the insulin protein molecules.
If I recall correctly, there is a Arrhenius type of relationship for the chemical reactions based on an exponential function of both time and temperature (and an activation energy).
It is clear that whatever temperature that you exposed the insulin to, the denaturing was at a very slow rate. It would be interesting to know exactly how time and temperature relate to the denaturing of insulin. I would guess that the insulin manufacturers know this.
While what you say is true, the issue is that the recommendation hasn’t changed much look at what the manufacturer’s recommend:
Insulin Glargine (Basaglar®): Throw away pen/vials after 28 days, even if it still has insulin left.
Insulin Lispro (Humalog®): Throw away pen/vials after 28 days of use, even if there is still insulin left.
Humulin R: Throw away vials after 31 days of use. If pen, throw away after 28 days.
Humulin N: Throw away vials after 31 days of use. If pen, throw away after 14 days.
Humulin 70/30: Throw away vials after 31 days of use. If pen, throw away after 10 days, even if it still has insulin left in it.
Insulin aspart (Fiasp®, Novolog®, NovoRapid®): Pen and vial, throw away after 28 days.
Insulin degludec injection (Tresiba®): Pen and vial, throw away after 56 days.
Insulin detemir injection (Levemir®): Pen and vial, throw away after 42 days.
Isophane insulin human suspension (Novilin® N NPH): Vial – 42 days; pen – 28 days.
Insulin human injection (Novolin® R): Vial – 42 days; pen – 28 days.
70% human insulin isophane suspension and 30% human insulin injection (Novolin® 70/30): Vial – 42 days; pen – 28 days.
Novolin NPH and R also represent the ReliOn ® brand available at Wal-Mart.
Insulin lispro injection (Admelog®): Pen and vial, throw away after 28 days
Insulin glulisine injection (Apidra®): 28 days
Insulin glargine injection (Lantus®): 28 days
Insulin glargine injection (Toujeo®): 28 days
It looks to me as if they tested to a point (many 28 days) and then stopped the test and said, look we are safe and efficacious out to the testing endpoint. There isn’t any rhyme or reason to it. We have personally shown that their recommendations are too conservative. There is no incentive to test farther because they like we when throw unused insulin away. Eric on this site used 5 year expired Humalog sitting at room temp for a year and it worked great. I personally think the recommendation to throw the stuff away is too conservative, and the recommendation is only being based on how far the manufacturer tested for the FDA and CE.
Weirdly, despite having a degree in Chemistry from a well known university, I don’t remember the Arrhenius equation. It’s probably more relevant to physical chemistry and, apparently, biochemistry so that may explain why; I’m basically an inorganic chemist, but I do have what would be a “minor” in US terms in biochemistry (i.e. I’m really not that good at it 
).
Insulin denaturization is actually well documented, there has been quite a lot of research. The problem with insulin, from the point of view of a chemist, is that its biochemical action depends on more than just the chemical formula (it’s “primary” structure); it depends on how the molecule folds upon itself; the tertiary structure. IRC that structure is actually formed as proto-insulin, which is then broken down chemically to form insulin.
How rapidly insulin degrades is probably described by the Arrhenius equation because the tertiary structure is maintained by, well, the secondary structure - the attractions of the various parts of the primary structure for each other. Temperature reduces these attractions.
A probably fairly authoritative article is here:
I particularly love this gem:
The significance of the Arrhenius equation for pharmaceutical companies is its ability to predict shelf lives of drug products based on short-term, accelerated storage stability studies at elevated temperatures. Such predictions can significantly shorten the development time, and products can be put on the market faster. Therefore, the Arrhenius equation has been (implicitly or explicitly) used widely for rapid and accurate assessment of stability of certain types of pharmaceutical dosage forms through accelerated aging studies.
There is a phrase, “Damning with faint praise.”
I didn’t read the whole article of course, I’m not quite that boring 
. But I did text search it for the word “insulin” 
The thirteen references took me back to one I had found earlier:
Zinc-free insulin, which is primarily dimeric at room temperature, unfolded at approximately 70 degrees C.
For the USians that is 158F.
So far as I can see the conclusion is that if you heat your insulin to, being conservative, 150F, you are dead. Below that you are, of course, still dead but it may take some time.
EH doesn’t keep track of how long he’s had Novolog kicking around in his bag. He estimates the longest he’s left it unrefrigerated and used it (fished out from the bottom of his travel kit) is six months. Three months is more standard. Thanks to @Eric we know it just lasts at room temp and we quit caring. The biggest issue is with Afrezza which I believe has a marked decay of efficacy after a month or so at room temperature.
@Sam, it sounds like a very exciting opportunity. EH recommends Wool & Prince brand shirts - they are amazing and basically don’t need washed. Good in hot or cold weather. Also I suggest this blog for light packing advice:
Has anyone used, refrigerated, expired Tresiba?
I came across some expired Tresiba in my refrigerator. It seems wasteful to discard them.
Current situation
I have somehow managed to run out of insulin tonight, and realised at midnight… of course. Thankfully, I remember putting an insulin Unused cartridge in a shaving bag I once carried. Key word, ‘once’.
Anyway, just injected myself with this insulin and long and behold… it’s working
No idea how old it is, must be over a year, two… possibly three years old. One thing I do know however, it is working. What DIDNT help actually, was the misconception that it would loose it’s potency. But that’s for a different story.
Nevertheless, nice review on this my friend. Clear and concise.
Hi @Ymello1! Welcome to FUD!
There are a lot of things we discover here from personal experience that sometimes go against what is taught by convention. Hopefully you can share some of your experiences with us as well. 
Eric
Agreed, this misconception frustrates me greatly, especially when people aren’t willing to believe the truth. Welcome to FUD!
I’m trying to calculate the amount of insulin that I’ve discarded after the 28 days. I think I’ve only ever emptied two Humalog pens. Nevermind the 90 day supply of Lantus that I left out of the fridge for a week by accident, and was told to discard. (And then had to buy full price because insurance doesn’t take human error into consideration.)
I’m not even going to attempt adding up the $$$$, or I’ll lose my mind.
Thank you for the info!
Definitely don’t lose your mind, but do conserve in the future. And if you happen to test another insulin that we haven’t for long term stability, we would love to know about it.
Thanks Eric for conducting yr high heat (I live in Australia - I know about heat!), long expired insulin experiment. For the first time in 40+ years T1 tonight I found myself without insulin - except for a very long expired vial. I searched for some advice & received the usual stuff about hypo & hyper, how long you should use insulin after it’s been opened but nothing about an emergency like having only expired insulin.
Thank goodness you did. I’m grateful and we’re all old enough to make our own decisions based on information we receive, which is something even diabetes organisations don’t recognise.
Thanks
Welcome to the forum! @Eric thrives on experimentation and invention: glad his findings helped you out!
Welcome @gmbunyan! Yes, I am so glad you found some useful information on our site. We have a number of Australian members, but could always use another.
G’day CatLady. I’m having a loved experience with grossly expired insulin & it’s working as well as current insulin! It’s 02:40am in Australia & I cant sleep because the Novo humalog (Expired 2012!) is driving my BGL down faster & harder than I anticipated. I really thought it’s efficacy would have reduced so I had more than usual. Wrong decision!
My experience clearly highlights the failure to focus on real emergency situations faced by PWDs every where.
If you’d like more info to share let me know.
I will be speaking with my diabetes organisation in Victoria (my home state) about the massive gaps in their data base.
I presume you are USA based. Whenever you are keep well. We’re out of our Covid crisis & I hope it’s not effecting you
All the best
Chrz
Gordon
Sorry you are up in the middle of the night. I suspect the losing it’s efficacy data is about the previous generation of insulin testing, and the companies just carried it forward because it was cheaper than actually doing the new study. If you capture a CGM trace, or just have a log with your notes and the amount of carbs it would be so helpful to others. Believe it or not, I have shared this information and been told that n=1 doesn’t amount to a hill of beans. Also, which insulin did you inject?