Mounjaro Kwikpen design changes April 2026 - What You Need to Know

Mar 26, 2026 Weight Loss

 

Rolling out from April 2026, Eli Lily, the manufacturer of the Mounjaro (Tirzepitide) Weight Loss Kwikpen, has modified the device to reduce leftover medicine and make it easier for patients to track that the final dose has been administered from the pen.

The new device works in the same way as the old Kwikpen; a new internal component has been added, meaning the plunger has been extended in length (see the images below).

 

 

 

This means that there will no longer be an excess of liquid remaining in the chamber, making it clearer when the pen should be discarded after the 4th and final dose has been administered. The 4 fixed 0.6ml doses in the Kwikpen (one administered weekly) remain the same

There may be a tiny amount of liquid remaining in the Kwikpen; you should not attempt to remove this from the device. 

Both pens will be available during the transition period. You cannot choose to receive the Original or Modified version of the Kwikpen you purchase, as the barcodes and packaging will remain the same; it is unknown to the distributor of the pen whether the old or new version is contained in the packaging. 

All strengths of the pen will be affected, and the time it will take to transition to the modified version is not available; it is expected to be completed over a period of months. 

 

Key points of change:

1. The Plunger Position - the plunger will sit further down the cartridge when the pen is unused. 
2. A new internal component has been added behind the plunger, which extends its length. This is shown in the image above. 
3. After the fourth and final dose, the plunger will be closer to the end of the pen, clearly indicating it is ready to be discarded. 

 

Will both devices be available at the same time?

Yes, both the original version of the Kwikpen and the new version of the Mounjaro Kwikpen will be on the market at the same time. When refilling your prescription, you may receive either version of the Kwikpen. Due to where pharmacies order from and where depots are situated, distribution and purchasing patterns across the country will differ, so it cannot be determined if you receive the new or old version of the Mounjaro Kwikpen. 

You cannot specifically order the original or modified version. This is the same for all dose strengths. The GTIN or Barcodes will remain the same.

If you need any advice about the new Mounajro Kwikpen device, call our friendly customer services team on 0208 262 3252.