How many doses are in the Mounjaro 7.5mg pen?

What the licensed prescribing guidance says about pen design and dose count

The Mounjaro Summary of Product Characteristics, published on the electronic Medicines Compendium, specifies that each KwikPen is a single-patient multi-dose device delivering four weekly subcutaneous injections. At the 7.5mg strength, each of those four injections contains 7.5mg of tirzepatide. The pen body is pre-filled and pre-set, there is no dial or adjustment mechanism. One pen equals one calendar month of treatment, assuming you inject once every seven days as directed.

Tirzepatide is a dual GIP and GLP-1 receptor agonist; it works by activating two gut-hormone pathways involved in appetite regulation and blood-sugar balance, and it slows gastric emptying to extend feelings of fullness. The clinical significance of the dose count is straightforward: running out of a pen mid-week or using doses more than once per week would take you outside the studied dosing schedule. The NHS tirzepatide patient page is the clearest public-facing summary of how the pen is used correctly, and the full SmPC on the eMC carries the prescribing detail your clinical team works from.

One practical point worth knowing: if you are wondering how many doses are in a Mounjaro pen, the answer is the same regardless of which dose you are on, and the last dose works identically to the first. There is no need to be cautious about a "nearly empty" pen, all four doses are fully pre-loaded from the moment you take it out of the fridge.

Where 7.5mg sits in the titration schedule, and why it matters for your pen order

A common misconception is that moving up a dose means the pen must contain more of the medicine in some physically obvious way. It does not. People often ask how many doses of Mounjaro they should expect per pen, and the answer is consistent across the entire range: four doses per pen, with the difference being how much tirzepatide is delivered per injection. Treatment typically starts at 2.5mg (a dose chosen specifically to help your body adjust rather than to produce weight loss) and moves through 5mg, 7.5mg, 10mg, 12.5mg and 15mg, generally in four-week steps under prescriber review.

Reaching 7.5mg means you will have completed roughly eight weeks at lower doses. Your prescriber assesses whether the move is appropriate, it is not automatic. The NICE technology appraisal TA1026 for tirzepatide notes that treatment should be reviewed if a patient is not tolerating the dose or if weight-loss progress after six months at the highest tolerated dose is below five percent. That review framework applies whether someone is at 7.5mg or 15mg. Knowing you receive one pen per month helps with both practical planning (ordering before you run out) and financial planning; you can read more about how Mounjaro is priced in the UK to understand what a month's supply typically involves.

If a dose is missed, the instruction is not to double up the following week. Specific missed-dose guidance is in the patient information leaflet inside the box; your prescriber and the leaflet together are the right source, not general advice online.

Storing the 7.5mg pen and knowing when it is finished

Mounjaro pens should be kept refrigerated at 2–8°C until first use. There is a limited window during which a pen can be kept at room temperature once removed from the fridge, the exact duration is stated in the patient information leaflet, and that is always the figure to follow rather than any third-party source, because storage requirements can be updated. Freezing the pen damages it; a pen that has been frozen should not be used.

When the pen is empty, the dose counter confirms it is finished and the mechanism will not fire again. Dispose of it in a sharps container, most local councils and GP surgeries offer sharps collection, and community pharmacies often accept them too. Keep used pens out of reach of children and do not recap the needle before disposal.

A question our prescribers hear fairly often is how many doses are in one Mounjaro pen and whether the amount remaining can be checked visually through the inspection window. In short: some pens have a dose counter window and some do not, depending on pen design, the leaflet or your pharmacist can confirm what to look for on your specific pen. Never attempt to reuse or re-fill a KwikPen; it is designed and licensed as a single-patient device.

Getting the right pen at the right time through a regulated service

Because each Mounjaro pen at any strength lasts exactly four weeks, your supply aligns neatly with monthly clinical reviews. Understanding how many doses are in a Mounjaro pen also helps you recognise why a regulated service aligns monthly dispatches with clinical reviews: a prescriber looks at your progress, tolerability and any side effects before your next pen is dispatched. That process is what makes a monthly subscription model from an unverified seller a red flag, genuine clinical oversight takes time and information, and a seller offering pens without a full clinical assessment is operating outside the law.

If you are thinking about starting Mounjaro or are already on treatment and considering your options, the Mounjaro overview covers eligibility, how the medicine works, and what to expect, while our weight-loss treatment page sets out how GLP-1 medicines fit into a broader approach. The clinical team at nume reviews every consultation personally, if you would like to check whether 7.5mg is an appropriate next step for you, or to start treatment from the beginning, check your eligibility with a free consultation.