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Troubleshooting Your Mounjaro Pen

05 May 2026
Troubleshooting Your Mounjaro Pen

Troubleshooting Your Mounjaro Pen

If your pen isn’t working as expected, the steps below cover the most common issues and how to resolve them.

If you are interested in getting started on your weight loss journey please click here to start a free consultation and see if our treatments plans are suitable for you.


Tips to prevent pen issues

  • Always follow the instructions provided with your pen
  • Never force the mechanism
  • Do not carry the pen loose where it may collect dust or debris
  • Never try to use the pen without a needle attached
  • Always use a new needle for each dose
  • Remove the needle after each use
  • Ensure the needle is straight and properly attached

Troubleshooting steps

Pen or dose knob is hard to push

  1. Remove any dust or debris from the pen
  2. Attach a new needle and ensure it is properly fitted
  3. Dial the dose knob back to 0
  4. Gently press the knob at 0 to release pressure
  5. Prime the pen according to instructions
  6. Press slowly and steadily
  7. Hold the button down for 10 seconds until the dose is delivered- 5 seconds seeTroubleshooting common Mounjaro® (tirzepatide) KwikPen® questions

Pen or dose knob is hard to twist

  1. Clear any debris around the mechanism
  2. Gently return the knob to 0
  3. Attach a new needle
  4. Prime the pen and try again

No liquid when priming

  1. Attach a new needle
  2. Ensure it is properly aligned
  3. Prime the pen
  4. Repeat priming up to two times if needed

**The KwikPen allows for the patient to attempt up to a total of 8 primes (if needed) and the delivery of 4 fixed doses of 0.6 mL. If the patient primes the KwikPen more than 8 times over the course of its use, it is possible that the patient will be unable to dial out to the Dosing Position “1” for the 4th and final dose.1

Unable to get the last dose

If you have taken all four doses:

  • The pen is complete and should be discarded
  • A small amount of liquid remaining is normal

If doses remain but the pen is not working:

  1. Attach a new needle
  2. Prime the pen (up to two times)
  3. Press fully and hold for 10 seconds- its 5 seconds - see Mounjaro® (tirzepatide) KwikPen®: Importance of priming the pen

Why is there liquid left in the pen?

Each pen contains a small amount of extra solution to allow for priming before each dose.

This ensures accurate dosing. The remaining liquid is not a usable dose.

Bulging or broken red seal

This is usually caused by pressure build-up.

If the seal is slightly bulging:

  1. Attach a new needle
  2. Dial back to 0
  3. Gently press the knob to release pressure

If the seal is broken or a needle won’t attach:

  • Do not use the pen
  • Contact support

Leakage during injection

This is usually caused by:

  • A poorly attached needle
  • Internal pressure build-up

Steps:

  1. Replace the needle
  2. Reset to 0 and release pressure
  3. If leakage continues, contact support

Still having issues?

If the steps above haven’t resolved the issue, contact our team with:

  • Date of first dose
  • Details of the issue
  • Whether leakage has occurred
  • Photos of the pen and red seal
  • A short video showing the issue

Do not dispose of the pen until advised.

If you have any issues and need to contact us please do so here. Alternatively if you are interested in seeing if weight loss treatments could help you speak to a clinician today.