Mounjaro Dosage Amounts: What the Evidence and Guidance Say

What the licensed dose schedule actually looks like

The NHS medicines page for tirzepatide sets out the same schedule that appears in the Summary of Product Characteristics: start at 2.5 mg for four weeks, then move to 5 mg for the next four, and continue upwards through 7.5 mg, 10 mg, 12.5 mg, and 15 mg at roughly monthly intervals if tolerated. Each step is a four-week pen. The pace is deliberate. Tirzepatide slows gastric emptying and alters appetite signalling across two gut-hormone pathways (GIP and GLP-1) and pushing the dose up too quickly amplifies nausea before the body has had time to adapt. The schedule is protective, not bureaucratic. A prescriber can slow the titration if side effects are significant, or hold a dose for longer if that seems clinically sensible. What they cannot do (and what no dosage guide should suggest) is advise you to skip steps or accelerate purely for speed. The information on the right Mounjaro dosage page covers the schedule in more detail, but the short version is straightforward: six doses, one starting point, one prescriber.

Why 2.5 mg exists, and what it is not

The 2.5 mg pen sometimes confuses people who expect to feel different straight away. It is the entry point because the body needs time to settle into the medicine's effects on gastric motility and appetite. Its job is adjustment. Clinical weight loss becomes meaningful at higher maintenance doses, which is why the SURMOUNT-1 figures (around 20% average reduction over 72 weeks) came from participants who reached 15 mg, not from the first pen. That context matters if you're reading about the 5 mg dose and wondering whether it will do anything: it can, and for some people 5 mg proves to be exactly the right long-term dose. The prescriber's job is to find your dose, not to get you to 15 mg as fast as possible. How much of the medicine each pen actually delivers in volume terms (which surprises a lot of people) is answered on our Mounjaro dosage in ml page.

The 15 mg ceiling and what the trial evidence tells us about higher doses

Fifteen milligrams is the maximum licensed dose in the UK. SURMOUNT-1 tested 5 mg, 10 mg, and 15 mg as maintenance doses against placebo. Average weight loss over 72 weeks was roughly 15% at 5 mg, around 19.5% at 10 mg, and approximately 20–21% at 15 mg, a meaningful step up at each level, though individual results varied considerably. Some participants lost significantly more; some less. NICE's appraisal of tirzepatide (TA1026) notes that continuing beyond six months requires at least 5% weight loss, if that hasn't happened at the highest tolerated dose, the prescriber reviews whether ongoing treatment is appropriate. There is no licensed dose above 15 mg; anyone suggesting otherwise is not describing a UK-authorised treatment. For more detail on what reaching the top of the schedule involves, the maximum dose of Mounjaro page covers the clinical picture fully.

Practical details: storage, the pen, and keeping your routine

Each KwikPen comes pre-filled and delivers the same dose every week for four weeks, there is nothing to measure or draw up. Injection sites rotate between the abdomen, thigh, and upper arm. The pens are stored in the fridge: many people find keeping the current pen in the fridge door, where it's immediately visible, makes the weekly injection easier to remember. For the exact room-temperature window if you're travelling or a pen is out of the fridge, the Patient Information Leaflet is the authority; a general dosage page cannot give you that number reliably because storage rules should be read from the current leaflet that comes with your pen. If you're curious how the doses convert for clinical record-keeping purposes, our Mounjaro dosage in units page explains the conventions. And if you've heard the term 'golden dose' and wondered what it means for you, our page on that looks at the evidence behind it. Cost is a reasonable question at this stage too, the Mounjaro cost page gives honest context on private pricing by dose.

Tirzepatide is a prescription-only medicine. A named prescriber (not automated software) reviews your consultation before any treatment is approved. If you'd like to understand whether you're eligible and which dose might be the right starting point for your situation, you're welcome to check your eligibility with our clinical team.