Why is there liquid left in my Mounjaro pen AFTER I've used all 4 doses?

Mounjaro - Leftover 5th Dose?

We are often asked...'there is liquid left / a dose left in my Mounjaro pen. I can't turn the dial anymore and nothing is coming out - help!'

It is also all over social media that this leftover liquid is a secret 5th dose which you can extract to use the pen for 5 weeks instead of 4 weeks. Eli Lilly have stated this is NOT an extra dose and should not be extracted, as the pen is only built / intended to administer 4 doses (which is why the plunger does not turn after 4 doses have been administered - the plunger is not meant to go all the way to the end of the glass vial containing the liquid, which means there is supposed to be leftover liquid).

But... why?

Before using Mounjaro, it is advisable to prime your pen... what does that mean? When you are using the pen each time, it is advisable in the instructions to squirt a tiny amount of the medication out of the needle.

This is a process called priming and ensures that there are no air bubbles in the syringe and that the needle is filled up with medication. Priming means you should always receive the correct dosage and improves the accuracy and effectiveness of the injection. It also ensures the needle is patent & working.

The glass vial in Mounjaro vial has a small amount of extra liquid to compensate for this process so that you are not left without the correct amount of medication. Please do not try to extract thius medication, as it could be dangerous to extracxt the medication for several reasons - infection, risk of contaminants, injury etc.

Please see a picture below of how your pen will look after each dose:

Mounjaro Dosing Guide - No 5th Dose

So there we have it! After much debate surrounding this extra fluid, Eli Lilly have confirmed that there will still be some fluid left in the pen - this is not an extra dose or the mystical "5th dose" mentioned on social media. Any questions, please give us a shout.

Thanks for reading!

The AJ Hill Aesthetics Team