Lantus after 28 days

My son is 5 and we are using Lantus pens for him. (Recently diagnosed). We just reached the end of our first 28 days and the Lantus pen has abt 100-120 units left. It seemed like such a waste to dump it, but I’m also not willing to “test it”. (Especially since one mn bcbs has $0 deductibles for formulary insulin.)

I am curious what folks do though- do they make a smaller size pen?


That’s a standard pen size, no smaller ones. But do you mean that it is bad after 28 days? They will be good for much longer in my experience. I’d use it up, and stockpile the new stuff


No, however it’s just “Insulin Glargine”, so there may be a smaller generic pen. (I should add, the generic probably isn’t in the formulary, so will be infinitely more expensive given that you are paying $0.)

Lantus is also available in 10ml vials, you could inject that using a “half unit” insulin syringe and while that requires more care than a pen it gives you half unit accuracy which, on a dose of just 7IU/day, may be worth having.

The 28 days thing is sound marketing; hospitals and doctors have to throw the things away after 28 days, so the manufacturer makes more money. After all the things cost $80 per pen in the US.


You wouldn’t be running any tests on your son. My son has carried Lantus around in a vial and injected himself with Lantus that is over a year past expiration and that has sat at room temperature for most of that time. I would keep using it until you have a stockpile large enough to weather any insurance/prescription snafu’s that will arise. Of course if it gets cloudy I would stop using it and move to the next pen.


As others have said, it’s fine for long after the 28 days!

Since this is new to you, I can understand your apprehension. But over time it will become more comfortable.

There are some rules that make sense to follow, and others that don’t. The 28 day rule is not really one that you have to follow.

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@Jess, welcome, BTW. You’ve come to a great place! I’ve learned a lot here.


Thanks all!

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