Reading a Mounjaro chart: doses, timelines and what the numbers mean

What does a Mounjaro dosing chart show, and what does it leave out?

A typical Mounjaro chart lays out the six UK dose strengths in ascending order and marks the minimum time spent at each one before a potential increase, usually four weeks. Laid out that way, reaching the highest dose from the starting point takes at minimum around 20 weeks, though many people stay at an intermediate dose for longer if it suits them clinically.

What a chart cannot show is individual response. Some people find 7.5 mg produces substantial weight loss with manageable side effects and never need to go further. Others titrate to 15 mg. The prescriber's job, at every step, is to weigh tolerability against benefit, a calculation no grid can make for you. If you are looking at a detailed breakdown of the Mounjaro dosing schedule, treat it as a reference, not a prescription.

Charts also do not capture timing in the real world. Orders placed before 12pm on a working day are dispatched the same day once clinically approved, which matters when a new pen is due and it happens to fall across a bank holiday or the day before you travel. Worth factoring in when you plan ahead.

One thing charts rarely include: the titration period is not wasted time. The body adapts to tirzepatide's appetite-suppressing and gastric-emptying effects gradually, and the stepped approach is specifically designed to keep gastrointestinal side effects manageable, including sensations like Mounjaro shivers, which some people notice as their dose increases.

How does a Mounjaro weight-loss chart translate trial data into real expectations?

The numbers on weight-loss charts typically come from the SURMOUNT programme, particularly SURMOUNT-1, a 72-week randomised trial involving 2,539 adults with obesity and no diabetes. At the 15 mg dose, average body-weight reduction was around 20–21%. The full SURMOUNT-1 paper is published in the New England Journal of Medicine for anyone who wants to read the methodology directly.

What charts rarely spell out is that these are averages across thousands of participants. The spread around that average is wide: some people lost considerably more, others less. A chart showing a smooth downward curve week by week is a model, not a prediction. Real weight loss on tirzepatide tends to be faster early on, can plateau for a stretch, and continues longer than many people expect before levelling out.

For a broader picture of what the evidence says across different doses, our Mounjaro weight-loss chart page works through the trial figures dose by dose. The key takeaway: the trial data supports meaningful, sustained weight loss for many adults, but the number that applies to you is determined by biology, lifestyle and consistent clinical review, not the chart itself.

NICE, in its technology appraisal of tirzepatide (TA1026), reviewed this evidence and recommended tirzepatide for eligible adults, noting that treatment should be reviewed if less than 5% weight loss is achieved after six months at the highest tolerated dose. That review threshold is the real-world equivalent of what a chart's projected curve promises.

What does a Mounjaro half-life chart tell you about how the medicine works?

A half-life chart shows how long tirzepatide stays active in the body after each weekly injection. Tirzepatide has a half-life of roughly five days, which is why once-weekly dosing maintains a reasonably stable level in the bloodstream between injections. After stopping treatment, the medicine clears gradually over several weeks rather than disappearing overnight.

This matters practically in a few situations: if you miss a dose, if you are preparing for surgery, or if you are thinking about contraception. For the surgery question specifically, NHS England's guidance on weight-management injections advises telling your anaesthetist you are taking tirzepatide before any procedure.

The half-life also explains why starting at 2.5 mg matters: steady-state levels build up over several weeks, so the early doses are both settling your system and establishing the baseline the medicine needs. Our page on the Mounjaro half-life goes into more detail if that context is useful.

For anyone curious about lower-than-licensed doses sometimes called microdosing, that sits outside standard clinical practice in the UK; the microdose chart page explains what is and is not known about that approach.

Who do these charts actually apply to, and what does eligibility look like?

The licensed eligibility for Mounjaro as a weight-management medicine in the UK is adults with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related health condition such as high blood pressure, raised cholesterol, prediabetes or obstructive sleep apnoea. Lower BMI thresholds can apply for some ethnic backgrounds under UK guidance, the NICE TA1026 recommendations set out the detail.

A chart of doses and timelines applies to anyone within that licensed group, but the step you start at and the speed you progress are always decided by a prescriber after reviewing your health history, current medicines and any relevant test results. BMI is the gateway; it is not the whole picture. Anyone who has had medullary thyroid carcinoma, pancreatitis or certain other conditions will need to discuss those specifically.

Mounjaro is a dual GIP and GLP-1 receptor agonist (the mechanism behind both the appetite reduction and the blood-sugar effects) and understanding that helps explain why the dose chart is graduated rather than fixed. If you want to understand more about how the treatment fits into the broader picture of medically supervised weight loss, that context may be useful before speaking to a prescriber.

If you are ready to find out whether Mounjaro is right for you, the next step is a free consultation reviewed the same day by a real clinician. Speak to our prescribers to get started.