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From Nashville, Tennessee, uSA:

I have a question about Lantus. The literature with the bottle says an opened vial must be used within 28 days, whether refrigerated or not. Since the unopened bottle has an expiration date that's over a year away, why the 28 day limit once I open the vial?

I use only nine units a day, so in a 28 day period that's 252 units. With 1000 units in a vial, I end up throwing away three-quarters of the medication. At $75 a vial, that's an expensive proposition.

I've seen news coverage that indicates that both food and medicine manufacturers often publish expiration dates that are much shorter than they need to be, just to force people to spend more money.

I know you aren't going to go on record advising me not to follow the manufacturer's recommendation, but what real risk would I run by using the vial until all the medication is gone? Doing that would require me to buy four vials per year versus 12 per year, a savings of $600 a year. To me, that's worth investigating.


The drug companies make recommendations that allow for handling of the insulin under the worst case scenario. Insulin is a peptide hormone. It is broken down by light, extreme heat and cold, and by time. When the insulin is stored outside of the refrigerator, the shelf life is less than when it is stored in the refrigerator. Clinically, we ask patients to replace their insulin when they note blood sugars rising for an unexplained reason. You might try using your insulin longer with a careful eye towards making sure your sugars stay in control.


Original posting 29 Jun 2006
Posted to Insulin Analogs


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Last Updated: Tuesday April 06, 2010 15:10:08
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