Mounjaro Pen Not Twisting, Clicking, or Turning to 1: What to Check

The Mounjaro KwikPen is a pre-filled, single-use device with a specific sequence of steps. If the pen is not twisting, clicking, or turning to 1, one of the following is almost always the cause.

The needle cap or base cap is still on

The pen must have the correct needle attached and the outer and inner needle caps removed in the right order before the dose knob will move. If any cap remains in place, the mechanism stays locked as a safety feature. Check your patient information leaflet for the exact cap-removal sequence.

The priming step has not been done first

Mounjaro pens require a priming step before the dose can be dialled. If the pen has not been primed successfully — confirmed by a small stream or drop of liquid appearing at the needle tip — the knob may not advance to position 1. For a step-by-step walkthrough of what priming involves, see the guide to priming your Mounjaro pen.

The pen mechanism is jammed or damaged

Occasionally, a pen may arrive with a mechanical fault, or may have been dropped or stored in a way that affects the mechanism. If the pen appears physically damaged or the knob simply will not move after all steps have been followed correctly, do not try to force it. More detail on what to do in that situation is covered in the guide on a jammed Mounjaro pen.

The pen has already been used

Each Mounjaro pen is a single-dose device. Once the dose has been delivered and the plunger is at the bottom, the pen cannot be reset or reused. If the knob will not turn at all and the pen looks fully depressed, it is likely already spent.

Checking your patient information leaflet

The step-by-step instructions provided with your pen are the definitive reference for handling and use. If anything in the sequence is unclear, the Mounjaro pen overview covers general handling points, and your prescriber or pharmacist can walk you through the process. For broader guidance on the medicine, the Mounjaro information hub is a useful starting point.

When a pen problem disrupts your usual injection routine, keeping a clear record of what happened matters more than you might think. GLP Trackr's dose logging feature lets you record each injection — including the date, dose strength, and whether a dose was delayed or missed — so you have an accurate picture to share with your prescriber at your next appointment.

If you end up needing to delay your dose while sorting out a faulty pen, logging that in the app means nothing gets lost or confused in your weekly schedule. The app also sends gentle reminders so your next scheduled dose stays on track once the issue is resolved.

Any decision about whether to proceed with a dose, delay it, or contact your prescriber is one to make with your healthcare professional — not based on the pen behaviour alone. If a pen appears faulty or damaged, contact your prescriber, pharmacist, or the manufacturer's helpline rather than attempting to use it.

If you notice a recurring problem with your pens, it may be worth reporting it through your national pharmacovigilance scheme (such as the UK's Yellow Card scheme) and mentioning it to your prescriber.

Keep a clear, dated record of every dose — including any that were disrupted — with GLP Trackr. Download it free on the App Store or Google Play and start a 7-day trial at no cost.