"Car baked" insulin. An experiment for Irish

Recently several members have posted about keeping their insulin cold.

I think this is largely an unneeded burden on diabetics, and a lot of unnecessary overhead. Storing insulin in your fridge is fine, but it shouldn’t cause anyone any concerns. I kept insulin UNrefrigerated for months at a time when in college. And even after college I kept it in a “wallet” I used to carry with syringes and a vial (before the pens). No problems.

So for the recent posts, I wanted to do something as a public service.

I went extreme! Last week I put some insulin in my car, windows up, parked outside in the sun. I live in Georgia. It is June…

The insulin was in the car for 4 days. I’ll say it again - I live in Georgia, and it is June. And then I put it in the house unrefrigerated for another few days.

I essentially had no basal left and no other insulin! My previous basal shot was 15 hours before this experiment. I was flat.

I took that “baked” insulin today. 5 units. Here is what it looked like. These are all BG tests on a top-notch meter (FreeStyle Lite):

12:17pm - 72
12:30pm - 64
12:43pm - 57
1:02pm - 49 (This felt like an impending death drop, so I started treating the low. I really felt like the bottom was dropping out here! Sorry to bail out on you folks so quickly, I really needed the sugar!)
1:07pm - 45
1:12pm - 39
1:15pm - 39

The science of the experiment ended when I went to the fridge. I didn’t track the carbs, I just went into survival mode and started a feeding frenzy. An ice cream bar, a half a bowl of whip cream, strawberry milk straight out of the carton (have no idea how much, just a bunch of swigs), and in honor of @docslotnick , one mini donut.

Possibly the only difference I saw was that it took a little longer.

For these type of experiments, you really need to use a meter instead of your CGM. Dexcom didn’t capture this very well, it never really saw the depth of the plummet. I was back on my way up before Dex figured it out. But I know everyone loves the graph pictures, so here is the obligatory CGM trace just for the heck of it:

So, is your insulin ever going to be subjected to that abuse? 4 days in a car in the sun?

Relax people. Your insulin is fine. I know keeping it in the sun at the beach is not preferable, and of course if you can put it in a cooler it is better. But don’t sweat it!

And one other thing - why is FUD the best? Where else do you get custom experiments meant just for your fellow members? That’s why FUD is different.

I dedicate this one to @Irish


So why the long list of do’s and don’t (not freezing or keeping in extreme heat) that insulin makers direct?

Novolog, for instance.

Same reason they tell you not to hold the blade end of a chainsaw. Or that you should wear safety goggles when using a letter opener. Everyone is worried about being sued.

Call me cray-cray, but today I opened a letter with no goggles! What a rush.


The FDA requires that handling and storage conditions as well as other things (like claims) have been approved by the FDA prior to marketing a drug or device. When a company wants to radically change the storage or handling conditions they would have to prove to the FDA that what they say is true. This would be expensive and would require lots of data collection and review.

If, on the other hand, you use storage and handling conditions that are similar to already approved drugs on the market, you will only have to do cursory testing, and that testing will be believed by the reviewers since it matches what they already know.

So if you were the product manager, would you spend a bunch of money to prove to the FDA that your drug is more robust than you say, or would you leave it alone, spend the least possible on this aspect and possibly reap a little reward when good insulin gets thrown away and more insulin is purchased?

Only when there is a belief that the company will make more money from proving this and having a claim that others can’t match, would they spend this money.

In my mind, this isn’t good or bad, it just is. To assume that everyone is pure good or pure evil is a mistake. Business is about money, and product managers try to manage a product to make the most money. Spending a bunch of money on a claim about storage conditions wouldn’t get you very far in your career.


Chris’ answer was better than mine! But I am still high on the rush of opening that letter…

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Not to mention the rush of knowing that insulin is way more robust from freezing and heating.

I am sorry to say, I got a little rush when I pushed the plunger on my son with the 4 units of previously frozen insulin. Probably not as much as that letter opener though, I may have to try that.


Yeah, and I held the wrong end of the chain saw. And now I’m retired.



My guess is that the odds of the insulin going bad do go up the worse the storage conditions. And when you have a ton of variability to deal with, why add another element?


I love this experiment because it makes me feel better about storage! I won’t feel so stressed when we go on vacation. Thanks, @Eric: I love your experiments!

But I am not going to stop using the fridge and taking precautions though :slight_smile: I feel like @TiaG : it is hard enough to figure out what is going wrong when your kid’s BG is going all over.

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Absolutely, I think storing insulin in a fridge is best. No reason to leave it in your car! :slight_smile:

I am simply trying to put minds at ease. When you carry insulin around a few hours in the airport or whatever, it’s fine. That was the reason for the demo.


I agree and have found similar results. When I was first diagnosed (42 years ago) I was told to keep insulin cold and did at first but eventually found that it wasn’t necessary. I will routinely keep the vial that I am using at room temperature and will use it until it is used up, which is long past the 30 day or so that is recommended. And when traveling I don’t worry about leaving my unopened vials un-refrigerated even in tropical climates like Central America, though I do try to keep them out of direct sunlight and heat (i.e. in my hotel room).

I will say that I am surprised by your result with car baked insulin; the only time I thought I had damaged my insulin was after a similar (inadvertent) test, but based on my experience I find it easy to believe.


Welcome to the community @jag1!

You have some of the longest seniority in the community: I think only @docslotnick and @Eric beat you. You should add your years to this thread: once we top 1,000, @Michel promised to buy beer (or non-intoxicants) to everyone for a whole evening in the next FUD meet :slight_smile:


Thank you. I just added my number - when beer is involved I’ll react quickly :slight_smile:


@Eric, you are wonderful! I was thoroughly entertained! And your experiment yielded some surprising results- really surprising. Thanks for being our resident guinea pig.


Would it be a violation of the TOS to say … Dude - you are Nuts !!!
[I mean that in the best possible way]

Quite the amusing post but on the serious side - very interesting. I may not be able to take that leap of faith for my child but I certainly appreciate your efforts and posting !!!


It is not a violation of the TOS, since we already know that Eric is nuts, but he is a really good nuts!

You may also find this one interesting re: our frozen insulin experiment which was inspired by good crazy Eric.


Dang. It is like tryouts for Myth Busters.


I am also remiss in not saying Welcome!! Really glad you are here and contributing.


Yeah - Eric pulled me over.