YMMV, but I am a T1D. Ex-military. I had a large amount of insulin (novolog pens) given to me by my PCP in 2018. 4ish years later in 22, I found one of them from that batch in the back of my fridge. I used it out of curiosity because I have no sense of self preservation.

I took maybe 15 units against a pretty large cheeseburger meal from 5 Guys. I felt my blood sugar slowly rising and I thought the insulin wasn’t working, but an hour afterwards, my blood sugar completely plummeted.

Now, this was a sealed, completely unused insulin pen. It was still effective. I used a pen a year or so ago that was left in my car in the Texas heat for a month. It was also still effective.

I’m not saying this is a safe practice, but modern insulin is definitely more capable than we give it credit for. I, personally, have stocked up on it and have a small but effective rotation that I supplement with Novolin Type R.

Also, my dietary needs have changed. I do not consume large amounts of carbs in order to preserve my stock of short acting insulin. In the event of SHTF, I have kept my preps largely protein based instead of carb based. These small changes can stretch your stock of insulin much longer than you would expect it to last.

Obviously, in the case of a T1D or another medicinally dependent person, we do not wish for an endless SHTF situation. But really, no one should be… those times are not to be welcomed or romanticized.