Mounjaro dosage chart for weight loss: the six-step titration schedule

Step 1, 2.5 mg: the adjustment phase (weeks 1–4)

Every person starting Mounjaro begins on the 2.5 mg pen, no matter what their prescriber expects the eventual maintenance dose to be. That isn't a low-ambition choice. Tirzepatide slows gastric emptying significantly, and starting at full strength would overwhelm most people's digestive system. The 2.5 mg month is about building tolerance: nausea, bloating and loose stools are commonest in the first few weeks after starting or increasing, and they almost always settle. Your prescriber will ask how you've got on before moving you forward. If side effects were significant, they may recommend staying at 2.5 mg for a second four-week cycle. There is no clinical benefit from rushing the titration; the injection dosage schedule is designed so that the weight loss arrives steadily rather than front-loaded. Most people notice appetite changes even at this starting strength, though the effect deepens considerably at higher doses.

Step 2, 5 mg through 12.5 mg: the escalation phase (months 2–5)

After the first four weeks, your prescriber increases the dose to 5 mg. If that is well tolerated, the next review moves you to 7.5 mg, then 10 mg, then 12.5 mg, each step spaced roughly one month apart. In practice, this four-month window is where most of the visible change happens. Appetite suppression becomes more pronounced, satiety signals arrive earlier in a meal, and weight reduction typically accelerates through this range. A useful way to think about it: the lower doses are the runway; the middle doses are where you reach cruising altitude. Not everyone needs to climb all the way to 15 mg. Some people find their appetite well controlled and side effects minimal at 7.5 mg or 10 mg and, with their prescriber's agreement, stay there. The 5 mg dose is often the first point where people notice the medicine doing something distinct from the starter phase, worth knowing so you're not caught off guard. The escalation period is also the right time to build the dietary habits that will support you long-term, since the appetite window the medicine opens is a tool, not a permanent override.

Step 3, 15 mg: the maintenance dose and what the evidence says

For those who reach it, 15 mg is the maximum licensed dose for weight management and the dose studied most extensively in clinical trials. In the SURMOUNT-1 trial (2,539 adults with obesity, 72 weeks) participants randomised to 15 mg saw average body-weight reductions of around 20–21%, as published in the New England Journal of Medicine. Those are group averages; individual results vary depending on starting weight, adherence, diet and activity. The maintenance phase is ongoing clinical work, not a finishing line. At every repeat order, a prescriber reviews your progress. If after six months at your highest tolerated dose the 5% threshold hasn't been met, NICE TA1026 guidance says continuing treatment should be reconsidered. That review protects you from months of a medicine that isn't helping. Some people do reach a plateau; the clinical conversation at that point is about whether to hold, adjust or stop. The concept of a "golden dose" is really just shorthand for the highest strength at which you tolerate treatment well and continue to see benefit, it's personal, not universal.

What the dosage chart means for cost and supply

The dose you're on directly affects what you pay. Higher-strength pens carry higher list prices, and since Eli Lilly adjusted UK pricing in September 2025, the gap between entry and maximum strength is considerable, reported private prices range roughly £149–£375 a month by dose and provider. A plain chart of that can make treatment look expensive at the top end, which is why it's worth reading a full breakdown of what those prices include before comparing figures. When you order through a regulated pharmacy like ours, what arrives is a pre-filled KwikPen in plain, unbranded packaging, with a DPD tracking link so you know exactly when it'll be at your door. The pen contains four doses (four weeks of treatment) and is refrigerated until you're ready to use it. The full Mounjaro overview covers storage and handling in more detail. One thing that catches people out: you can't simply request a higher dose because a lower one is out of stock or because you've decided you're ready. Evidence of your current dose and clinical review are required before any increase. It sounds administrative, but it's the safeguard that makes the titration schedule safe rather than theoretical. If you're weighing up treatment options more broadly, our treatment overview sets out what's available and what the differences are.