I have a couple of questions regarding insulin lifespan. My doctor told me that once opened, insulin lasts the same amount of time at room temp as it does in the fridge. She also said that the max amount of time insulin lasts is 40 days, so I should throw out any insulin that old and start a new bottle.
Is it really true that, once opened, insulin degrades at the same rate at room temp vs. the fridge? This seems to violate laws of chemistry, but maybe someone can answer this question who has better knowledge than my non-expert surmising? And if the degredations rates are the same, why is that?
What are others’ experiences with how long insulin lasts? I’ve marked when I start a new bottle (I use Lantus and Humalog), and they never seem to lose potency for as long as it takes me to finish a whole vial, about 2.5 months. To see if this is merely me not noticing a gradual decrease in potency, I’ve paid attention to when I open a new vial to see how potent it seems in comparison, and no, there doesn’t seem to be any difference (i.e. no sudden increase in potency relative to my “old” vials). I hate to waste money as well as stuff that seems perfectly fine. Others’ thoughts/experiences?..