Humalog and Lyumjev are both lispro insulins. The difference is the acid used in Lyumjev to stimulate blood flow at the injection site for faster absorption.
Often, this is not noticed with pen injections. But in a pump, where there’s a relatively continuous infusion and occasional bolus infusions at the same place, Lyumjev can become painful.
Some people adjust to it. I have not.
Those who like the performance of Lyumjev but find it too uncomfortable to use in an insulin pump might try mixing Humalog and Lyumjev to reduce the bite. I know of one person that does a 1:1 ratio of the two, and another person who does 3:1 Humalog to Lyumjev (25% Lyumjev).
I am using a 3:1 mix right now. It feels like full strength Lyumjev.
My first go with Humalog was just 100% Humalog so I could assess how I respond to it. There was no pain. In fact, I didn’t feel boluses at all. I did notice the difference in timing, but it was super minor and easy to adjust to.
Even though I am now no longer planning to mix Lyumjev and Humalog, this was still a successful experiment because I learned something. And that’s good! I now have a path forward with my insulin use, and honestly, keeping it simple with something I’m pretty sure will work fine feels a bit better anyway.
One thing I’ve learned in the management of my illnesses is experimentation to find the best management is part of it.