Mounjaro (Eli Lilly) Plungers

thingiverse

After disassembling the autoinjector, you can use the custom length plungers to deliver either 1/3rd, 1/2, 2/3rds or the full dose of the 5ml of liquid in the glass syringe. Remove the air bubble first. I designed these by measuring several Mounjaro glass syringes both before and after injection. I figured out the travel length and then divided it into 1/3, 1/2, and 2/3rd. I made the full length plunger a little longer than necessary to ensure every bit of medicine can be extracted. These print nicely in PLA. You may want to adjust the infill to be higher where the diameter necks down. They're fragile in shear, so they'll break if bent, but work fine when used in compression as a plunger inside the glass syringe.