Why won't my Mounjaro pen turn to 1?

If the dose knob on a Mounjaro KwikPen will not turn until 1 shows, there is not enough medicine left for a full dose. Each KwikPen gives 4 doses. Do not try to use what is left: start a new pen.

Why is my pen not clicking?

The clicks are not how the pen measures your dose. On a Mounjaro KwikPen, turn the knob until it stops at 1, which is one full dose, and check the window shows 0 after. The Wegovy, Ozempic and Saxenda leaflets say not to set your dose by counting clicks: read the dose counter instead.

The counter or window did not go back to 0. What now?

The full dose has not gone in. On a KwikPen, put the needle back in and push the knob until it stops, without redialling the dose. On a Wegovy, Ozempic or Saxenda pen, keep pressing the dose button until the counter shows 0. If it still will not reach 0, ask your prescriber or pharmacist.

I think I missed part of my dose. Should I inject again?

No. Do not inject again to make up for it, because you could take too much. Follow the step above to finish the dose if the counter has not reached 0, and if you are unsure, ask your prescriber or pharmacist what to do.

My Mounjaro pen has no dose knob. Is that right?

In the UK, Mounjaro comes as the KwikPen, which has a dose knob. If your pen looks different, do not use it until you have checked with the pharmacist who supplied it. You can report a suspected fake medicine through the Yellow Card scheme.

Pen not working? Mounjaro and Wegovy troubleshooting

Most pen problems come down to a few things: not enough medicine left, priming, or reading the dose counter rather than the clicks. Here are the fixes from the UK leaflets, and when the answer is simply to start a new pen.

Last updated 3 November 2026

The short version

Won’t turn to 1 (Mounjaro): the pen is empty of a full dose. Each KwikPen has 4 doses. Start a new pen.
Not clicking: clicks do not set the dose. Read the dose counter, or turn the KwikPen knob until it stops at 1.
Counter did not reach 0: the full dose has not gone in. Finish it without redialling; never reinject to top up.
Want it step by step? The pen troubleshooter walks your exact pen and shows a 3D pen.

It will not turn to my dose

On a Mounjaro KwikPen, if the knob will not turn until 1 shows, the pen does not have a full dose left. Each KwikPen holds 4 doses, so this usually means it is finished. Start a new pen rather than trying to use what remains. On a Wegovy, Ozempic or Saxenda pen, if the dose selector will not reach your dose, there is not enough left for a full dose either, so move to a new pen.

It is not clicking, or I want to count clicks

The clicks are not how any of these pens measure a dose. On the Mounjaro KwikPen you turn the dose knob until it stops at 1, which is one full fixed dose, then check the window reads 0 after you inject. On the Wegovy, Ozempic and Saxenda pens the leaflets are explicit: do not set your dose by counting clicks, read the dose counter. Never try to count clicks to take a smaller dose. If you think your dose should change, talk to your prescriber.

Priming and the flow check

The Mounjaro KwikPen is primed before every injection: turn the knob until it shows the prime symbol, point the needle up, tap out air, and push until a drop appears and the window shows 0. The Wegovy, Ozempic and Saxenda pens only need a flow check before the first injection with each new pen, not every time. If no drop appears, fit a new needle and try the prime or flow check again.

It is jammed, or the counter did not go to 0

If the pen is hard to press, check the needle is fitted straight and is not blocked; a fresh needle often fixes it. If you have injected but the counter or window did not return to 0, the full dose has not gone in. Keep the needle in and keep pressing (KwikPen: push the knob until it stops, without redialling) until it reads 0. Do not reinject to make up a dose. If it still will not reach 0, speak to your prescriber or pharmacist.

If the pen itself looks wrong

If a pen does not match the leaflet in your pack, for example a Mounjaro pen with no dose knob, do not use it and check with the pharmacy that supplied it. You can report a suspected fake or faulty medicine to the MHRA through the Yellow Card scheme. If you bought it without a prescription, read how to spot an illegal seller.

Common questions

Why won't my Mounjaro pen turn to 1?: If the dose knob on a Mounjaro KwikPen will not turn until 1 shows, there is not enough medicine left for a full dose. Each KwikPen gives 4 doses. Do not try to use what is left: start a new pen.
Why is my pen not clicking?: The clicks are not how the pen measures your dose. On a Mounjaro KwikPen, turn the knob until it stops at 1, which is one full dose, and check the window shows 0 after. The Wegovy, Ozempic and Saxenda leaflets say not to set your dose by counting clicks: read the dose counter instead.
The counter or window did not go back to 0. What now?: The full dose has not gone in. On a KwikPen, put the needle back in and push the knob until it stops, without redialling the dose. On a Wegovy, Ozempic or Saxenda pen, keep pressing the dose button until the counter shows 0. If it still will not reach 0, ask your prescriber or pharmacist.
I think I missed part of my dose. Should I inject again?: No. Do not inject again to make up for it, because you could take too much. Follow the step above to finish the dose if the counter has not reached 0, and if you are unsure, ask your prescriber or pharmacist what to do.
My Mounjaro pen has no dose knob. Is that right?: In the UK, Mounjaro comes as the KwikPen, which has a dose knob. If your pen looks different, do not use it until you have checked with the pharmacist who supplied it. You can report a suspected fake medicine through the Yellow Card scheme.

Sources

Steps are from the UK patient leaflets and instructions for use as of 3 November 2026. Always follow the leaflet in your own pack. This is general guidance, not medical advice.