Results of mixing some Humalog with Novalog in a cartridge

I am not suggesting doing this on purpose. The other day I drew out the last of a vial of Novalog getting about 80% of what was needed. I went to the fridge to get a new vial and grabbed the one remaining vial of Humalog in error. I drew the rest needed to fill the cartridge my usual amount.

It wasn’t until I was finished with the change that I realized what I had done. I thought, well you always were one to experiment, let’s see how it works. I saw no difference in BG management. I don’t think that anyone should do this on purpose.

The plus to all this is I really need to use that Humalog before it gets out of date. I didn’t see any noticeable changes between Humalog and Novalog except that Humalog is more stubborn about clinging to an air bubble in the syringe. It is harder to purge that air before filling the cartridge.

Anyway, I will use up this last vial of Humalog without mixing any Novalog with it😁


I can’t see any problems with doing that. It might slightly affect the delivery curve from what you are used to, but those two insulin’s are very similar.


I still use some Humalog that is 5 years expired and it works great. It’s been kept in the refrigerator. The only sign of anything wrong is the pen itself doesn’t push down as easily as it used to.


I’m just glad that I didn’t grab the backup vial of Lantus. I believe I would’ve started over.


When on MDI I used to purposely keep my Humalog in a pen and the Lantus in a vial. I did things so automatically in the morning before work I was always worried I would grab the wrong one and mix them up. The Lantus comes in a pen :slightly_smiling_face: