If there was a rulebook devoted to the do’s and don’ts of life with diabetes…it would be quite the tome. I imagine it to be as long as the fifth Harry Potter book, which had 766 pages and weighed just shy of 3 pounds, though it would certainly not be as engaging of a read.

As I started to visualize a diabetes rulebook, I started thinking about the actual rules it would list out. It would cover the basics, for sure, of life with diabetes, like “count carbs at every meal” and “remember to take your insulin”. But it would also get into the minutia – the things that aren’t so obvious, even to those who are fairly well-versed in diabetes. Things that I didn’t know until adulthood, like how glycemic index, alcohol, caffeine, dawn phenomenon, and so much more can affect blood sugar levels.

Yeah, it would definitely be a boring-ass read.

But as I was coming up with a seemingly endless mental list of diabetes rules, it stuck out to me that there’s one that I don’t follow. In fact, I’m not sure that I ever followed it. And that rule pertains to insulin.

The rule is about how if you open a vial of insulin, it’s best to use it within a 30-day (or maybe it’s 28-day) window. I think it’s because manufacturers claim it loses its potency after that timeframe passes, but to me, it’s a bunch of BS.

Maybe I do go through whole vials of insulin in a one-month period, or maybe I don’t. I have no clue, I don’t keep track of my supplies to that extent. But what I do know is that “expiration dates” and “best by” labels aren’t always based on exact science. I’ve totally eaten my fair share of “expired” foods (things like granola bars or cans of soup, definitely not wilted spinach leaves or moldy yogurt) because I use my common sense when making judgment calls about consuming those items. For me, it works kind of the same way with insulin. As long as an insulin vial has been properly stored since opening it (in a refrigerator’s butter compartment, because of course), then I feel safe using it beyond a 30-day period – again, within reason, using logic (I doubt that I’d use insulin dated YEARS ago).

I’ve even heard of folks using insulin that’s past it’s expiry date, and while I haven’t done that myself, I can’t say I blame anyone for trying to use up every last drop of the stuff when it’s in possession and it’s necessary to take. It’s too expensive to waste.

So if by breaking this “rule” makes me or other people rebels, I’ll don the title with pride…and smirk to myself as I think about other diabetes rules (ahem, pertaining to prolonging CGM sensor life, or using sites other than the abdomen for my Dexcom, or hardly ever remembering to change my lancets…) that I’ve broken over the years.