How 1.7mg Wegovy Compares to Mounjaro: Doses, Data and Decisions

Where 1.7mg sits in the Wegovy schedule — and why it matters for any comparison

The Wegovy titration pathway, as licensed by the MHRA, runs 0.25mg, 0.5mg, 1.0mg, 1.7mg and then 2.4mg, with roughly four weeks at each level. The 1.7mg dose is the penultimate step: patients spend approximately one month there before moving to the 2.4mg maintenance dose, assuming they tolerate it well. This means most people on 1.7mg are in a transitional phase, not yet at the dose where the bulk of clinical-trial weight loss was recorded.

The STEP 1 trial (a 68-week study published in the New England Journal of Medicine) measured outcomes at 2.4mg maintenance, not at intermediate doses. Average weight reduction across the trial was around 15% of body weight. That is the figure that underpins Wegovy's UK licence for weight management, and it is the correct benchmark for comparing semaglutide's potential, not a single month at 1.7mg.

Mounjaro's dose schedule starts at 2.5mg for the first four weeks, not as a therapeutic target but as a period of adjustment, and rises through 5mg, 7.5mg, 10mg, 12.5mg and 15mg. The SURMOUNT-1 trial reported average weight reductions of around 20–21% at the 15mg maintenance dose over 72 weeks, cited by NICE in its appraisal of tirzepatide (TA1026). Mounjaro also activates both GIP and GLP-1 receptors (the only dual-agonist weight-loss medicine currently licensed in the UK) while Wegovy acts on GLP-1 alone.

So a comparison of "1.7mg Wegovy versus Mounjaro" is, in clinical terms, a comparison of a transitional semaglutide dose against a medicine that will eventually reach its own therapeutic ceiling. If you are considering moving from 1.7mg Wegovy to Mounjaro, it is more useful to think about the full trajectories rather than a snapshot at a single transitional dose.

Head-to-head data: what SURMOUNT-5 found when the two medicines met directly

A question our prescribers hear most weeks is whether one medicine is simply better than the other. The SURMOUNT-5 trial, published in the New England Journal of Medicine in 2025, is the only randomised head-to-head to have compared tirzepatide directly against semaglutide 2.4mg in adults with obesity but without type 2 diabetes. Over 72 weeks, tirzepatide produced greater average weight reduction than semaglutide at its standard maintenance dose. NICE's committee discussion notes that indirect comparisons across the trial programme also favour tirzepatide. That is meaningful evidence, and it is the most direct answer available to the question of how these two medicines compare at their respective maintenance doses.

That said, neither medicine is right for everyone. Wegovy's GLP-1 mechanism has a longer clinical track record, and individual responses to both treatments vary considerably. The full Wegovy versus Mounjaro comparison covers the mechanisms, eligibility differences and trial evidence in more depth if you want to look at the broader picture before your consultation.

It is also worth noting that the Wegovy programme now extends to a 7.2mg maintenance dose, approved by the MHRA in January 2026 (with a dedicated single-dose pen approved in April 2026). At 7.2mg, trial data reported average weight loss of around 20.7% over 72 weeks, narrowing the gap with tirzepatide's highest dose considerably. Dose availability at this level is confirmed during the clinical consultation.

Eligibility thresholds and what private access looks like for each

Both medicines share the same private licensed eligibility criteria: adults aged 18 or over with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, dyslipidaemia or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. A prescriber assesses the full clinical picture, BMI alone does not determine suitability.

If you are thinking about switching from one to the other, or wondering which to start with, our page on how 1mg Wegovy compares to Mounjaro explains the clinical considerations in detail. It is not a straightforward milligram-for-milligram swap; the two medicines work differently and the prescriber's view of your history matters.

For context on what private treatment costs across these two options, this page compares the cost of Wegovy and Mounjaro in plain terms. Both are prescription medicines, and legitimate pricing always includes a clinical assessment.

The broader dose comparison between Wegovy and Mounjaro covers how the titration schedules differ across the full range, which is the most useful frame if you are weighing up the two treatments at the start of your decision.

Side effects at this stage of treatment, what to expect

Both medicines share a broadly similar GI-led side-effect profile: nausea, constipation, diarrhoea, indigestion and fatigue are among the most commonly reported, as listed on the NHS medicines page for semaglutide. These effects tend to be most noticeable in the first week or two after starting or increasing a dose, which is one reason titration schedules are gradual.

At the 1.7mg stage of Wegovy, some patients experience a temporary uptick in side effects as the body adjusts to the higher dose before settling. The same pattern applies to each new Mounjaro dose step. Neither is inherently easier to tolerate at the population level, individual experience varies.

If you experience severe, persistent abdominal pain that radiates towards the back, seek urgent medical attention. The MHRA highlighted acute pancreatitis as a known, if infrequent, risk associated with GLP-1 medicines in its January 2026 Drug Safety Update. Side effects and suspected reactions can be reported via the MHRA Yellow Card scheme.

Which medicine suits you is a clinical decision our prescribers make with you, based on your full medical history, current dose, and goals. Start your free consultation and a GPhC-registered prescriber will review your answers the same day.