What happens if you use an insulin pen that's out of date?

Answer 1

Insulin is a fragile molecule and can be broken down by light, heat, or even motion. The expiry date isn't a precise guess about when the insulin will stop working, but as insulin approaches and passes its expiry date, it will become less and less effective.

Answer 2

according to this site (http://www.diabetescareguide.com/en/medications.html), insulin loses strength when out of date. This would appear to be true as I have just realised why my blood sugars been high this week - my insulins out of date! Oops...

Answer 3

Yes it does