Mounjaro Click Chart: mg Per Click

What a Mounjaro KwikPen actually is

The KwikPen is a multiple-dose pre-filled pen holding four doses of 0.6 mL — 2.4 mL in total — supplied at 2.5, 5, 7.5, 10, 12.5 and 15 mg per dose. The MHRA approved the four-dose KwikPen on 25 January 2024 and described it as covering a month's treatment. That is the device the whole click-chart question is about: four doses in one barrel.

The other tirzepatide presentation is a single-dose pen (and a single-dose vial), delivering 2.5–15 mg in 0.5 mL with nothing to dial and nothing to count at all. US and UK readers arguing about clicks are very often describing two different devices — which is also part of what separates Mounjaro vs Ozempic in the UK from the US conversation.

What no regulatory document says is how many clicks any of this takes. The UK SmPC, the UK patient information leaflet and the US prescribing information all describe whole 0.6 mL doses; none of them contains a click count, and none gives an instruction for delivering less than a full dose. The manufacturer is not silent, though. Eli Lilly's own KwikPen FAQ states that "the Mounjaro KwikPen Instructions for Use do not provide instructions for dialing a dose less than the full fixed dose, and therefore this is not recommended". So everything below is arithmetic on a community assumption, not a licensed dosing method — which is the argument laid out in why Lilly says not to count pen clicks.

Mounjaro click chart: mg per click, by pen strength

One caveat before the numbers, because it decides how to read them. On a KwikPen you set the dose by turning the knob until it stops and a dose icon appears in the window, and the MHRA-approved Instructions for Use describe that icon as equal to one full 0.6 mL dose. There are no numbered increments and no partial position to stop at. So the fractional columns below are not settings you can select — they are here to price a borrowed click count, and show what a number copied off a forum would be worth on your strength.

Taking the community 60-clicks-to-a-full-dose figure at face value, one click would be 0.01 mL. On that assumption:

Read down the 1 click column first. The same movement of the dial is worth six times as much drug on a 15 mg pen as on a 2.5 mg pen, because every strength packs its milligrams into the same 0.6 mL. There is no such thing as "the mg in a click" — only the mg in a click on your strength.

Then read across the rows. Most of these fractional values are not licensed doses at all: on a 7.5 mg or 12.5 mg pen, nothing short of the full dose is an amount that appears on any label. The 10 mg row is the coincidence that fuels the whole idea — its quarters land on 2.5, 5, 7.5 and 10 mg, because 10 divides evenly by the 2.5 mg titration step. Every one of those already exists as its own pen, which is rather the point: the arithmetic works and the device still will not do it.

The leftover nobody's chart mentions

The UK patient information leaflet says, in as many words: "A small amount of medicine may remain in the pen after all doses have been correctly given. Do not try to use any remaining medicine."

Now the arithmetic. The pen holds 2.4 mL as four doses of 0.6 mL, and that accounting only works if every dose is a whole one. Deliver part of a dose and the remainder stops being a clean number of doses — while the device gives no readout of how much went in or how much is left. This injection and the next one both become estimates. That consequence comes straight off the leaflet, and click charts routinely omit it.

Where click counting is real

Genuine click dosing exists in a different product class: compounded tirzepatide dispensed in a multi-dose click pen, where each click advances the plunger by a fixed volume. Because a click is 0.01 mL and a U-100 syringe unit is also 0.01 mL, a click chart and a syringe-unit chart are the same numbers — which is why the tirzepatide mg to units on a U-100 syringe calculator answers both questions at once. The formula:

clicks = (dose in mg ÷ concentration in mg/mL) × 100 × clicks per unit

On the common pens one click equals one unit, so clicks and units are the same number. Some pens use two units per click, which halves the count. There is no standardised click-to-milligram ratio across compounders, so the ratio has to come from the pharmacy that dispensed your specific pen — the same warning applies to Zepbound pen clicks.

The failure mode: clicks do not come in fractions

A pen stops at whole clicks. On a compounded pen at 34 mg/mL, 2.5 mg works out at 7.4 clicks and 5 mg at 14.7. Neither exists. Round 14.7 down to 14 and you deliver 4.76 mg; round up to 15 and you deliver 5.10 mg. The absolute error is one click every time, but its share of the dose grows as the count shrinks — which is why a concentrated pen is a poor match for a small dose.

A dilute pen has the opposite problem at the top: at 10 mg/mL, 15 mg is 1.5 mL, more than a full 100-unit syringe holds and a large volume to put under the skin in one go. If your dose and your pen do not produce a whole, sensible click count, that is a dispensing question for your pharmacist, not a rounding decision to make at the kitchen table.

What the label actually specifies

Tirzepatide is prescribed on a ladder, not a continuum. Treatment starts at 2.5 mg once weekly — a starting dose, not a maintenance dose — and increases in 2.5 mg steps with at least four weeks at each step. Recommended maintenance doses are 5, 10 and 15 mg; 7.5 mg and 12.5 mg exist as escalation rungs on the way up. You can map the 2.5 mg tirzepatide ladder onto your calendar to see where each rung lands. The label also allows a late shot inside a fixed window — the four-day missed-dose window on the tirzepatide label covers that case.

Every dose you could be prescribed already exists as a manufactured fixed strength — which is why the usual reason to want an in-between amount is not arithmetic at all. It is that one rung is doing too little and the next is doing too much, the pattern behind food noise coming back on 5 mg Mounjaro. That is a prescribing conversation, and it is a better one to have than a dial.

Where this tool does not apply

None of it applies to the single-dose pen or the single-dose vial: 0.5 mL, no dial, nothing to count. Part-dialling or splitting a KwikPen is something Lilly explicitly does not recommend, which makes it a prescriber conversation rather than a kitchen-table rounding decision — if a smaller or more frequent dose is what you are after, see split a weekly tirzepatide dose and what splitting a weekly GLP-1 dose actually does to your levels. And every number above is only as good as the 60-click assumption behind it. Confirm it against the Instructions for Use supplied with your pen, along with the concentration and click ratio, before you dial anything.