How many clicks is 3.75 mg on a Mounjaro pen?

Step 1, Understanding what each click actually represents

Mounjaro is dispensed in a pre-filled KwikPen. The standard UK strengths run from 2.5 mg through to 15 mg, and each pen is calibrated differently. On the 5 mg KwikPen, the dose dial moves in increments of 1.25 mg per click. That gives you four possible positions: 1.25 mg, 2.5 mg, 3.75 mg, and the full 5 mg. So if your prescriber has asked you to dial 3.75 mg, you are turning to the second click, not the third, not the fourth.

A common misconception is that the numbers printed on the pen barrel indicate dose volume rather than the total medicine in the cartridge. They do not. The barrel label tells you the pen's maximum strength. The dose is set entirely by rotating the cap until you feel and hear the correct number of clicks. For a clear breakdown of how volume and dose relate on this pen, the millilitre equivalent of 3.75 mg is worth reading alongside this.

The NHS medicines guidance for tirzepatide, published on the NHS website, confirms that Mounjaro is supplied as a pre-filled pen and that dosing instructions are specified in the Patient Information Leaflet included with your medicine. That leaflet is the definitive reference for your specific pen.

Step 2, Dialling the dose correctly before you inject

Once you have confirmed which pen you are holding, the process runs the same way each week. Remove the cap, attach a fresh needle, then rotate the dose dial slowly and deliberately. On the 5 mg pen, you will feel a distinct click at each 1.25 mg increment. Stop at the second click for 3.75 mg. The dose window on the side of the pen will show a marking that corresponds to that position, if the window looks blank or shows nothing legible, do not inject; contact your prescriber or pharmacy first.

It is worth knowing that the 2.5 mg starting dose uses a different pen (a dedicated 2.5 mg KwikPen) so if you have recently moved from the starter pen, the click increments will feel different. The 2.5 mg click count on the 5 mg pen follows a different pattern from the 2.5 mg pen used at treatment start.

Always inject into a freshly cleaned site (abdomen, thigh, or upper arm) and rotate locations week to week. Press the injection button fully, hold for the count recommended in your leaflet, then withdraw. Never re-cap a used needle; place it in a sharps container and dispose of it according to local council guidance.

Step 3, Checking you have the right pen for this dose

Not every pen strength supports a 3.75 mg setting cleanly. On the 5 mg pen it lands exactly at click two. On a 7.5 mg pen, each click represents a larger increment, so 3.75 mg cannot be dialled precisely. This matters: if your prescriber has prescribed 3.75 mg, they will have specified which pen strength to use alongside that instruction. If you have been given a pen that does not match, call your pharmacy before proceeding.

If you want to compare the 3.75 mg position to the full 5 mg dose, our guide to how many clicks 5 mg takes sets out the differences clearly. And if you are working from a 5 mg pen but trying to confirm the equivalent of a 3.75 mg draw for the first time, the dedicated 3.75 mg on 5 mg pen page has a more detailed pen-specific walkthrough.

Mounjaro is a Black Triangle (▼) medicine under additional MHRA monitoring; any suspected side effects or concerns about dose accuracy can be reported at yellowcard.mhra.gov.uk.

When to speak to your prescriber rather than adjust yourself

A question about click counts sometimes masks a deeper concern, that the current dose is not working well enough, or that side effects are making the standard titration difficult. Both are legitimate clinical conversations, not things to manage by guessing at the dial. Prescribers sometimes suggest an intermediate dose like 3.75 mg precisely to smooth the step from 2.5 mg to 5 mg, but that guidance needs to come from them in writing, not from a forum post or a packaging assumption.

If you are on 15 mg and finding the dose less effective over time, that is a different matter entirely and warrants a proper review rather than a dosing workaround, our guide to weight gain on 15 mg Mounjaro covers what the evidence says and when to escalate. More broadly, the full picture of what Mounjaro is, how it works, and what the clinical evidence shows is on our Mounjaro overview page.

For context on how UK pricing affects access decisions, particularly following the price changes announced in 2025, the Eli Lilly price increase explainer is worth a read. Cost should never be the reason someone dials an unauthorised dose to stretch a pen further, that risks both inaccurate dosing and wasted medicine.

If you have questions about your specific dose or whether your current titration plan is right for you, a conversation with a prescriber is the straightforward next step. At nume, a real clinician reads every consultation personally, speak to our prescribers and get a same-day clinical review.