The end of the insulin vial/cartridge

I use Humalog cartridges (penfills), and they last me over a month. I’ve noted before, when I was on Lantus and Humalog, that the last cartridge out of the package of five cartridges seemed to be less potent than the rest, but I never thought much of it. My control was so erratic that it wasn’t something I could pin down definitely.

Now, however, I’m on a pump and using only Humalog. And in the past few days I’ve been running high almost all day. Today is the worst, no matter what I’ve done I can’t get my blood sugar below about 9 mmol/l. I’ve used over 12 units in corrections (which is a lot–my TDD is usually 40-45 units), upped my basal rates, lowered carb ratios, and nothing has worked. Last night I ate a pretty high-carb dinner and then was hit with highs of 18-20 that needed about three corrections before they would even budge, and stayed up there for hours.

I just realized today while trying to figure out what the problem might be (and trying not to get frustrated!) that a few days ago I switched to the final cartridge of Humalog. Just wondering if anyone else finds that this happens. The entire pack of five cartridges (1500 units) lasts me about five or six weeks usually. Even though I hate wasting insulin I might have to start chucking it when the month is up and starting new stuff. Or maybe I’ll start buying bottles since they have less insulin, and just buying occasional penfills for my backup Humalog pen.


Where do you keep your insulin before you use it?

When I started insulin I was using Ultralente, which was discontinued, so I bought all I could find figuring I’d use it until it ran out because it worked so well for me. Unfortunately, after a few months it started going bad until it didn’t work at all… UL is supposed to be very stable. Then I switched to R and had the same problem. My vials would go dead while there was still a lot left (I only used a couple units per meal.)

Finally someone online figured out what the problem was. I was keeping my unused insulin in the butter compartment as instructed (with a thermometer to make sure it didn’t freeze.) But I have a large, newfangled fridge with huge door compartments full of stuff. Every time the door of the fridge slammed, everything in the door was vibrating back and forth for a few seconds. You could hear the noise of all the bottles hitting each other. Well, turns out that if you shake insulin a lot, it can go bad and that was what was happening.

I moved the insulin to the lower fridge shelf in the main compartment in the fridge and NEVER had another vial go bad on me. Too bad I didn’t learn that before I lost 6 vials of UL!

I keep most of it in the door of the fridge, but I also keep a cartridge in my backup Humalog pen that is in my purse (when I refill my pump I use the cartridge in the pen to refill and replace the one in the pen with one from the fridge). Interesting about the shaking, though. Maybe I’ll try keeping it in another part of the fridge!

Oh! I have my insulin in the butter compartment too. Never had a problem, but good info to know. I’ll switch it. Thanks.


If you keep your insulin in the body of the fridge, it’s a good idea to buy one of those cheapie small thermometers to make sure it isn’t freezing. My fridge will freeze things on the top shelf from time to time, but the bottom shelf doesn’t drop below 39 degrees.

I think the fridge door is okay if you have one of the smaller old fashioned fridges like I used to have. My new one has room for full sized soda bottles, milk, etc on the door. It’s very poorly designed–the stress of the stuff rattling around actually broke the plastic retaining barrier on one of the shelves.

I have not found issues related to the insulin going bad but as a pump user i have found that my site will go bad and cause the same effect. If i put my sites to close to together in my abdimon and stay on one side to long my sites become less effective, When this happens i usually change sites and sides of my belly and it usually fixes it.

Another thing that can cause this is some sort of infection. I had a respratory infection and had the same simptoms.

i find the same about a site gone bad…anytime i continue to run high after taking a correction bolus, i always take a shot to make sure i get the insulin. i usually wont trust a new site if i am super high…a shot assures me that the insulin has been delivered.

One bottle lasts me about 5 weeks…i generally dont even have a problem with the bottom of the bottle and effectiveness. And have not seen any issues with keeping my unopened vials on the door of the fridge.

Good luck.

How long do u use your vials for?

I agree. When I was on the pump for two years, I would get days when I just couldn’t get my BG to go down. It turned out to be an allergic reaction to the catheters, as well as infections in my sites because of the allergy and including antibody insulin resistance.

Yeah, complex stuff.

Sometimes it’s just a bad tube. Toss the tube when that happens, and put in a new one. It takes a few minutes to do, and wastes a bit of inulin, but if the insulin is coming out of the new tube, at lest you can guarantee it’s not a pump problem. Sometimes the insulin gets clogged in there.

Jennifer- Also, is it hot where you are? My doctor told me that while he was living in Texas as a diabetes practitioner, that he would get many complaints about Humalog becoming “thick” and having trouble getting through the pump tubing. He said whenever it’s excessively hot temperatures, Humalog has trouble functioning with the pump. He suggested the Novolog didn’t seem to have this same problem with heat.

If you’re on the pump and your BGs are high and won’t go down, the likely culprit is your infusion site. If after two boluses you don’t seem to be getting a reaction, change infusion sites rather then changing basal rates and adding more correction boluses.