Tandem Diabetes Care announced that the t:slim X2 insulin pump is now FDA-cleared for use with Lyumjev® (insulin lispro-aabc injection), Eli Lilly’s ultra-rapid acting insulin. This gives U.S. users another option for faster insulin action paired with Tandem’s Control-IQ+ algorithm. The news follows European Union clearance in late 2024, highlighting Tandem’s effort to expand pump compatibility worldwide.

Lyumjev achieves its speed by including additional ingredients that help insulin absorb more quickly into the bloodstream compared to Humalog and Novolog. Experts we’ve spoken to often describe it as a “Humalog version 1.5”—built on the same backbone but with a faster onset of action.

It’s important to note that some users report a burning sensation when using Lyumjev. Our editor Justin Eastzer personally experiences this, but tolerability can vary from person to person. For those who do well with Lyumjev, the pairing with t:slim X2 could be a meaningful upgrade.

With this clearance, the t:slim X2 now supports Humalog, Novolog, and Lyumjev U-100 insulins. Whether Lyumjev becomes a go-to choice for pump users will likely depend on individual experience, but this move expands the options available for people with diabetes in the U.S.

Disclaimer: Diabetech content is not medical advice—it’s for educational purposes only. Always consult with a physician before making changes to your healthcare.