Home Diabetes Care Does Insulin Really Go Bad After 28 Days?

Does Insulin Really Go Bad After 28 Days?

Does Insulin Really Go Bad After 28 Days?

Medically reviewed by Anna Goldman, MD.

*DISCLAIMER: This is just not medical advice. The creator is just not a health care provider, pharmacist, or chemist. This text is just not a guide to managing insulin but a take a look at different opinions, research, and guidelines regarding insulin expiration dates and temperature limits.

Despite being often called one among the “strongest” hormones within the human body, insulin may also be pretty darn fragile. Like Goldilocks rummaging through the bears’ house, the positive print in your insulin vial or pen says it could’t be too hot, too cold, or too old.

Time and temperature can each play a giant role within the potency of your insulin, and insulin that isn’t stored in perfect conditions have to be thrown away — in response to the manufacturers. But some independent research and anecdotal patient experiences say otherwise! The reality is that many members of the diabetes community repeatedly use insulin beyond the 30-day limit, although opinions differ on the wisdom of this approach.

Insulin may be catastrophically expensive, which might make throwing a partially used vial or pen into the trash a tragic event. For some people, especially those within the developing world, using insulin beyond its expiration date may almost be a medical necessity. 

Does an opened vial of insulin really go bad after 30 days? Does just a few hours in the recent sun or the bitter cold really kill insulin whether it’s been opened or not? Let’s take a more in-depth take a look at the official guidelines vs. the real-life experience and independent research.

What the Paperwork Says: 28 to 30 Days for Opened Insulin

In accordance with most manufacturers’ official guidelines, insulin starts to degrade — and must be disposed of — 28 to 30 days after it’s been opened.

It definitely is sensible. Insulin is a protein. It will definitely “spoils” — even though it doesn’t lose its potency . As a substitute, it regularly becomes weaker and weaker. Actually, insulin starts degrading immediately upon opening, however the degradation could be very slow in the primary 28 to 30 days. You actually won’t notice it.

While you pass that 28- to 30-day window, it degrades more quickly. 

  • If you happen to often finish a vial or pen of insulin inside 30 days, you don’t must pay much attention to what number of days it’s been because you opened it.
  • If you happen to don’t often finish a vial or pen inside 30 days, don’t be surprised if days beyond 30 leave you feeling frustrated with stubborn highs that won’t budge. 

Almost certainly, the more sensitive you’re to insulin, the more likely you’re to note when its potency is fading. 

How Long Does Insulin Really Last?

What happens when you ignore that 28- to 30-day timeframe? I’ve been talking to people about diabetes for 20 years, and I can let you know that there’s no consensus. Some people say nothing happens: Insulin continues to work just positive! Others say they see a noticeable difference; you’ll discover a broad mixture of opinions whenever you take a look at this topic within the Diabetes Day by day forums!

Must you toss your insulin after 30 days? Perhaps not and here’s why: It’s not going to go from 100 to 0 potency. As a substitute, it’s a gradual decline. Likelihood is you may get more out of it.

Independent research says insulin could last potentially 4 times longer than the medication guidelines suggest. In 2023, a global group of scientists tested quite a lot of insulins in real-world unrefrigerated conditions in India, during a season during which temperatures repeatedly reached as high as 95 degrees Fahrenheit. All the insulins retained at the very least 90 percent potency after 4 months, and most retained greater than 95 percent potency. The insulins fared even higher when placed into clay pots to maintain cool.

A spokesman for the researchers said, “If our results may be confirmed in larger studies, it might drive a change within the requirement to discard insulin kept outside a fridge after one month. The period when insulin should be used can potentially, in that case, be prolonged to 3 or maybe even 4 months.”

Extreme Heat and Cold 

Also within the manufacturers’ medication paperwork are loads of warnings about temperature limits. The paperwork says temperatures which can be too hot or too cold can destroy the potency of your insulin in only just a few hours of exposure.

Ideally, insulin must be stored within the refrigerator when it’s not getting used, and the temperature in your fridge must be between 36 to 46 degrees Fahrenheit. 

The rules say insulin can tolerate temperatures as much as 77 degrees and as cold as 36 degrees, but ideally not for long. The longer your insulin is at a temperature above 46 degrees, the more likely it’s degrading. And insulin, similar to water, freezes solid at 32 degrees; even after defrosting, it might be radically altered and unreliable. 

Is It Really Too Hot for Your Insulin?

Some research suggests that prime temperatures are rarely a major problem for insulin safety and potency.

In lots of parts of the world, it’s very difficult to guard insulin from temperatures over 77 degrees. A 2021 study led by Doctors Without Borders got down to test the accuracy of those heat limits in real-world conditions at Kenya’s Dagahaley refugee camp, where refrigeration is scarce.

Actually, the temperature on this area hits a typical every day high of around 98.6 degrees and barely falls below 77 degrees, even at night. As Diabetes Day by day editor Ross Wollen explains in his review of this study, in response to the manufacturers’ instructions, no insulin should give you the chance to endure these conditions for long. 

After one month, though, “all of those insulins were fully and equally potent. The insulin that warmed up to just about 100 degrees F — not only once, but each day for a month — was just positive!” They kept the study going for a complete of 12 weeks, and the outcomes held up: All of the insulin was still potent.

My Take

Insulin doesn’t go bad immediately when it reaches its expiration date. In case your vial is barely half-empty, and it’ll take one other month before you utilize it up, you would possibly notice it’s not as effective during those last couple of weeks. And if that happens? Well, then toss it.

Almost certainly, your insulin remains to be going to be relatively effective, but it should proceed to degrade. The more sensitive you’re to insulin, the more likely you’ll notice it losing its potency.

What about heat? Personally, I’ve left a pack of three cartridges of Afrezza inhaled insulin in my automotive for several weeks during a hot July summer. I did this on purpose and desired to see the way it impacted the potency. I used a cartridge and located no change in its efficacy.

So possibly heat doesn’t matter quite as much as we’ve been told? Although, it’s still value stashing your insulin kit within the shade whilst you’re hanging on the beach. (And when you like hot tubs: Don’t let your insulin pump or patch dip into the water of a hot tub! Yikes! No must boil insulin.)

But I even have experienced the harmful consequences of damaged insulin from extreme cold.

In highschool, I worked on the local movie show. That is December in Hanover, Latest Hampshire. The temperature outside was well below freezing, and I used to be tasked with stringing up Christmas lights on the marquee letter board out front. I also needed to update the marquee with the films coming that Friday.

I used to be outside with my insulin pump in my jacket pocket for at the very least an hour.

Little did I do know, the freezing temps were destroying my insulin quickly. My blood sugars seemed perfectly positive through the evening. It didn’t even cross my mind to be nervous. Mind you, this was across the yr 2004, before diabetes blogs or continuous glucose monitors (CGM).

I woke up the following morning in diabetic ketoacidosis (DKA), and my blood sugar was within the 500s. All night, I’d been getting damaged, weak insulin. I puked 15 times before finally going to the emergency room. 

And that, my friends, is slightly old story about insulin temperature. So, I’m pretty darn careful with my insulin in extreme cold because DKA is just not fun.

Okay, so possibly we will meet in the center. Possibly you don’t toss your insulin out after 30 days but you just keep a more in-depth eye on its efficacy. If you happen to’re experiencing stubborn highs, possibly your insulin has lost a few of its potency. 

If you happen to’re nervous about it, listed below are just a few easy methods of maintaining a tally of the calendar:

  • Use a everlasting marker to put in writing the date you opened it directly on the vial or pen. Do that the moment you open that vial or pen. Just get within the habit of it.
  • Mark your kitchen calendar with an “Insulin is finished!” form of note. (Yes, some people do still have calendars pinned to the wall!)  
  • Set a reminder in your phone or other “smart” devices. “Hey, Alexa, tell me on June 30 at 7 a.m. that my insulin is 28 days old.” Personally, I take advantage of my Amazon Echo to remind me of nearly every little thing because I’m getting old.
  • Put an old-school Post-it note within the fridge compartment where you store your insulin and write the “opened” date. Then just keep updating that Post-it note.

Ah, insulin. We depend on it so desperately to maintain us alive and yet it’s so darn finicky. Possibly you shouldn’t toss that expensive stuff into the trash just due to the calendar or hot temps. Watch out and be protected, and look closely at how your blood sugars are doing.


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