I have been told many times and was told by my endo that an insulin pen is only good for 28 days however, the Levemir instruction manual that comes in the pen box states that it is good for 42 days. How often do you open a new pen?
I got same info but if you use it past 30 days you will see a difference at least i did. Most of the time a pen never last more than 5 to 6 days for me.
Yeah I was thinking prob toss it after 28 just to ensure its fresh, wow you must use a lot of insulin!lol
I don’t know about the throw-away pens, but my penfill can be used for 6 weeks…