Question about humalog going bad

I use a humalog pen for my type 2 diabetes. I keep it refrigerared until I start using that pen. It has always stayed good out of fridge for as long as I needed it. About 4 days ago I noticed my blood sugar rising, even after taking the humalog. Last night I took my humalog and went to bed. When I got up my blood sugar was 200 (normally about 120 after fasting) so I immediately took a double shot of humalog. Checked blood sugar 30 minutes and 1 hour after taking, and sugar was still 200. Got a new pen out of fridge and took a shot, and within 30 minutes sugar was back to normal. My question is-can humalog go bad? It had only been out of fridge about 3 weeks, and new pen I used was from same box.

Any insulin can go bad. It’s rare but by no means unique. Temperature has a lot to do with it; that’s one reason I keep mine refrigerated all the time, open or not. But three weeks is unusual. Has your weather been unusually warm?

Then again, it could just be a batch that was borderline to begin with. Yet another possibility is that it was improperly stored before you bought it. That, also, is rare but not unheard of.

David: Do you keep a pen that you are using in the fridge too? I am in Georgia, and even with AC the house is still hot. It would break the bank to run the AC lower than 80 degrees during the day. I would like to keep the pens I am using in fridge, but insert says not to, and I am not sure what to do. Thanks for any advice in advance.

I think you’ll be fine as long as you don’t go much longer than a month. I’ve travelled to some hot places with my pump, including Israel, Jordan and Turkey in the summer. I had a Frio pack but wasn’t using it properly, and had no way of cooling the insulin once it was in my pump. I had no problems whatsoever until my last day, 5 weeks after arriving. I couldn’t get my blood sugar below 12 (216) no matter how much I took, but prior to that day it worked as well as on day 1.

Well, in the first place I don’t use pens, I use vials and syringes. But yes, I keep all my insulin refrigerated all the time, whether it’s been opened or not. It’s not unusual for a vial to last 60 to 90 days. Why pen users should be told not to do this, I don’t know. Perhaps it has something to do with the inner mechanism in a pen. Just speculating, I really do not know.

I’m with @David_dns on this one - I keep all my insulin in the fridge all the time (unless it’s in my pump, or being carried in a Frio pouch).

It’s interesting that Lily says, “Store opened vials in the refrigerator or at room temperature below 86°F (30°C) for up to 28 days.” While for the kwikpen it says, “Store opened vials at room temperature below 86°F (30°C) for up to 28 days.” Is there something in the kwikpen mechanism that might malfunction taking it in and out of the fridge? Seems unlikely to me, but …

I would probably consider this a one-time problem, but if it continues, I would ensure the pen isn’t in a place that gets over 86°F as the day wears on. I might also write the date I opened the pen on the side of the pen.

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Is the date good on it or close to expire? You mentioned you took a dose and 1 hr later you dosed again with different pen. With the overlap it should have brought you down fast almost double stacked.

For me 1 pen last a week so I leave it out of the fridge. When I used Vials I always left them in the fridge as cold or room temp insulin never bothered me and the vial lasted me longer. Also some days I just have higher insulin resistance and it takes more insulin on those days.

I’m in a cold climate and Humalog never goes bad during the winter, but it occasionally does during the summer. I think the warmer ambient temperature causes it to age faster in the summer months. I wish there was some way to test insulin. Unfortunately, I work through a lot of variables before I decide the med is bad. It takes a while. Frusterating.

I had the same problem yesterday, I took Humalog to bring my numbers down & instead I was getting higher (it was around dinner so maybe I didn’t give myself enough normally before dinner I only give 3 units tho) so I don’t know why that happened it was rising quickly. I did read online it could be that the pen needed changing so I got a new one out of the fridge… I hope today I don’t have the same issue. I get nervous taking too much insulin as it is as I get worried that I’m going to go into a low. This is all still so new to me, so lots of learning along the way…

From time to time, I have wondered whether my Humulog had gone bad. Happened a week or so ago, in fact. My sugars were at or close to 200 for almost 24 hours. And this is on a very low carb eating plan that keeps my sugars in the 70 to 140 range a good bit of the time. My last A1c was 5.8

But I’ve found on multiple occasions that this same suspect vial of insulin starts working again. I don’t use a pen and I don’t refrigerate the current vial. So a week after my excursion for 24 hours, I’m still using that same vial. I keep my home in the low to mid 70’s. My insulin usage probably at least doubled during this excursion period, trying to get my numbers back down. And then everything returned to normal since then.

These extended high excursions don’t happen often. I think I’m on my eighth Libre sensor now and I believe I’ve only had this one extended episode.