Like a lot of people on here, I use Novolog from a pen. I’m lucky in that I don’t need much. In fact, I just went a whole two weeks without needing any. But now I’m getting some highs and needing to correct. The pen I’ve been using is over 4 weeks old now, but I’ve maybe only used 25 units out of a possible 300. I know that the manufacturer says to only use it for 4 week and then toss it. So I’d like to know what other people do. I hate to waste 275 units of insulin if it’s still good. But should I just get rid of it and open a new pen? Or should I just keep using it for as long as I can? What do you do?
I use it until the behavior seems to be getting enough slower that it makes it difficult to calculate what my dosing should be. That said, I don’t have much experience. I use a pen of fast acting about every 2.5 weeks. It was only for several months last year that I had two pens open at once - one of Apidra and one of Humalog. I used the Apidra when meals included more fast-acting carbs and used Humalog when I was going to have something like chili or pasta that could use the greater delay and longer tail. I think on several occasions I ended up with Humalog being almost 6 weeks since opening. Only once did I have to toss one before I used it up - and that time I had been keeping it in my desk drawer which is only two or three feet from a portable heater. After that I kept it across the room where the temperature rarely gets over 68 degrees F.
I take only 8 units of Lantus a day, so on that I always get more than 30 days out of it. A couple of years ago I was taking only 6 units daily, and often got about six weeks out of a pen. That said, because I have such a low need for basal (only about 25% of my TDD), if it did get a bit weaker at the end, I’d probably just think I’d missed my carb counting a bit and wouldn’t notice it. Someone with a higher basal need would likely notice any change more readily. Again, I keep my insulin in the coolest room in the house, so even in the summer room temperature is fairly cool.
I don’t use that much insulin either. My current pen (Novolog) I started on 1/31… and it is getting low. Very typical that I get 2 months out of pen. I would keep using as long as you can. With your low usage I would keep the pen in the frig as much as possible…maybe extend the life. When your BG starts getting wonky then it is time to change. Just my 2 cents worth.
I am insulin resistant so I go through tons of insulin but when I was going through insulin type changes (Novolin to Lantus and Humalog…vials to pens then back to vials, etc.) I held on to unused insulin just in case. I kept it for a year before I tossed it.
I use novorapid for my fast acting. Don’t know how long 1 pen lasts, but it can be months… I just keep using it until it’s finished or until I notice it is not working, whichever comes first.
My tresiba pens are typically finished within 1 month - 6 weeks (depending how agreeable and cooperative my pancreas is feeling at any particular time). … so no problem there…
I use a lot more insulin that you do, and almost never reach the 4-week point before finishing a pen. I do, however, have experience living in the Arizona desert…where I would always forget my kit in my gym bag when running into the grocery store in the 110-degree heat. So I have a lot of experience using insulin that I suspected may be spoiled.
One thing that I learned was that insulin sort of becomes less effective/potent…but it doesn’t just turn into water. So before I would realize a pen had gone bad, I would usually have a few crummy days of high numbers, but not so high that I would immediately suspect bad insulin. My mind would first go to bad carb-counts or inaccurate dose.
I use vials, not pens, and unlike some folks I keep all my insulin refrigerated all the time. I typically get 60 to 90 days’ use from a vial and thus far have not had one go bad.
but when I was going through insulin type changes (Novolin to Lantus and Humalog…vials to pens then back to vials, etc.) I held on to unused insulin just in case. I kept it for a year before I tossed it.