When people notice my OmniPod insulin pump, the first question that I’m asked is “what IS that?”

After I explain that it’s my insulin pump, and it’s called a pod, the second question I’m asked is some variation of “how long does it last?”

The canned answer that I provide is something about having to change it every three days, because that’s how the OmniPod is advertised.

But I’ve used this pump for years now and never bothered to really test this three-day limit. I’ve known for a long time that my pod works a handful of hours after the expiration alarm starts chiming, but I wasn’t sure about exactly how many hours I had before a pod expired for good.

So, the other day, I decided to find out.

My pod expired at 10:22 A.M. Since I prefer to change my pods in the evening, I figured it was the perfect time for this little experiment, assuming that the pod really would last me for the majority of the day.

And, well, it did! At 10:22 on the dot, the pod beeped at me to notify me that it was expired. And in the six hours after that, it would alarm every hour (on the 22nd minute) to remind me, time and time again, that it was expired. In the seventh hour – beginning at 5:22 P.M. – my PDM started chirping at me on and off every 15 minutes or so. First it was because I was running out of insulin, but then it was to really get the point across that my pod was expired!

I was determined to use every last drop of insulin in the pod, though, so I bolused for my dinner around 5:45 and I was pleased to discover that I got my full dose of insulin without any issues. As I was cleaning up after dinner, that’s when the signature OmniPod BEEEEEEEEEEEEEEEEEP went off as one blaring, unceasing alarm. I checked the time: 6:22 P.M.

So there was my answer. An OmniPod can last precisely 80 hours after you initially activate it for the first time (or in other words, 8 hours after you receive the first expiration message)…as long as it still has insulin in it. It’s definitely something good to know for sure now, because in the future, it might come in handy and help me avoid wasting precious insulin.