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From Paris, France:

I'm 23 and I've had Type 1 diabetes for 9 months. Right now, I seem to be reaching the end of the so-called Honeymoon period. My current treatment is 2 shots a day (one for breakfast, one for dinner) of a 20/80 mix (Mixtard 20 from Novo Nordisk). I also use Humalog when needed to cover bigger than usual lunches. I've been doing this for a month now, keeping my Humalog pen at room temperature, and today, I found out that the month old pen of Humalog is totally ineffective.

I've read that one shouldn't keep insulin at room temperature for more than 28 days. Could you please tell me why? I've also read than I shouldn't keep an insulin pen in the fridge between shots. Why, since keeping the cartridge in the fridge is OK? (Since I'm only using Humalog when needed, there's no way I'll use an entire cartridge in just a month, and I hate wasting.)


This is an interesting question. You are following manufacturers' advice by discarding unrefrigerated insulin after a month and by keeping unused insulin in the fridge. You don't need to keep the insulin you are currently using in the fridge but I would be very surprised if it didn't work after only a month unless you had inadvertently left it in strong sunlight or on a radiator. Apparently insulin injected straight from the fridge is more likely to be painful.


Original posting 23 Feb 1998
Posted to Insulin


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Last Updated: Tuesday April 06, 2010 15:08:56
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