The Different Doses of Mounjaro and How the Schedule Works

Why six doses, and what the SURMOUNT trial data shows

The SURMOUNT-1 trial, published in the New England Journal of Medicine, randomised 2,539 adults with obesity across three maintenance doses: 5 mg, 10 mg, and 15 mg. Average weight reduction after 72 weeks was roughly 15% at 5 mg, around 19% at 10 mg, and approximately 20–21% at 15 mg. The gap between doses is real but not enormous — which matters when a patient reaches their highest well-tolerated dose rather than the maximum. The trial did not include 2.5 mg as a long-term maintenance dose; that strength exists solely to ease the body into treatment during the first four weeks.

The dose-response relationship is the reason NICE's recommendation of tirzepatide (TA1026) specifies that if less than 5% weight loss is achieved after six months at the highest tolerated dose, continuing treatment is reviewed. Higher isn't always achievable, and for many people, 7.5 mg or 10 mg becomes their effective long-term dose, which is one reason it helps to understand what the different doses of Mounjaro are before starting treatment. The prescriber's job is to find that point, not simply to push toward 15 mg.

For a plain summary of the full licensed dose range, the NHS tirzepatide medicines page is a reliable starting point.

What actually happens at each step of the titration schedule

A question our prescribers hear most weeks is whether staying at a lower dose forever is an option. The answer is yes, if the prescriber is satisfied with the clinical picture, there is no obligation to reach 15 mg. The titration schedule works roughly like this in practice: 2.5 mg for weeks 1–4 (settling the system), then 5 mg for weeks 5–8, with subsequent four-weekly increases if the prescriber judges it appropriate and the patient is tolerating the current dose well.

The most common reason to pause titration is gastrointestinal side effects: nausea, constipation, or reflux that hasn't settled. Staying at a dose for an additional four weeks before moving up is a recognised clinical approach. Jumping a rung is not recommended, and splitting or halving a pen to approximate an intermediate dose carries real risks, the reasons a half-dose isn't a safe workaround are worth understanding if that question has crossed your mind.

Equally, some people wonder whether staying at 2.5 mg long-term makes sense. That page covers the clinical reasoning in detail. The short version: 2.5 mg was never tested as a maintenance dose in the trials, so the evidence base for doing so is thin.

The practical difference between the lower and upper doses

Moving from 2.5 mg to 5 mg is the transition from a tolerability dose to a therapeutic one. Most people notice appetite suppression meaningfully from 5 mg onward. The difference between 2.5 mg and 5 mg is worth reading before that first dose increase, particularly if nausea has been a factor.

Between 5 mg and the higher doses, the incremental benefit in weight loss is measurable but smaller per step. The side-effect profile tends to be most pronounced immediately after each increase, then settles within one to two weeks for most people. Injection sites rotate across the abdomen, thigh, and upper arm; the pen itself is the same design at every strength, so handling doesn't change as the dose goes up.

One practical cost note: Eli Lilly adjusted UK list prices from September 2025, with higher doses carrying notably higher list prices. For context on what that means for private prescriptions, the breakdown of the Eli Lilly UK price increase is a useful reference. The short version is that higher doses cost more per pen, which is relevant when weighing how long titration might take and what that means for monthly spend.

How dose decisions are made at a regulated UK pharmacy

Mounjaro is a Prescription Only Medicine. No dose increase happens automatically. At nume, every repeat supply is assessed by a GPhC-registered Independent Prescriber before dispatch, and dose increases require supporting evidence, not just a patient request. That clinical checkpoint is deliberate: the SURMOUNT programme showed that titration done at the right pace produces better tolerability outcomes, and rushing it undermines the results the trial was built to demonstrate.

If you're thinking about starting treatment or moving between doses, the right first step is a clinical assessment. You can check your eligibility and start a free consultation, a prescriber will review your answers the same day and determine the appropriate starting point for you specifically. The full picture of what Mounjaro treatment involves, from mechanism to aftercare, is covered on the Mounjaro treatment overview.