Is Mounjaro 10 mg Equivalent to Wegovy? The Comparison Explained

The biggest misconception: dose numbers across two different medicines do not compare directly

The most common misreading of this comparison is assuming that a higher milligram number on one medicine signals a stronger or equivalent dose on the other. It does not. Tirzepatide (Mounjaro) and semaglutide (Wegovy) have entirely different molecular weights, receptor targets and dose ranges, so 10 mg of one cannot be read as the counterpart of any specific figure from the other.

Mounjaro is a dual GIP and GLP-1 receptor agonist, the only medicine of its kind licensed in the UK for weight management. Wegovy activates the GLP-1 pathway alone. Because they work differently, their dose ladders are designed independently of each other. Mounjaro runs from 2.5 mg to 15 mg across six steps; Wegovy's weight-loss schedule reaches 2.4 mg as its standard maintenance dose — a number that looks far lower but reflects a different pharmacological profile entirely. The question of how doses across these two medicines relate needs a clinical frame, not a simple arithmetic one.

Framing 10 mg Mounjaro as "equivalent" to 2.4 mg Wegovy is a shorthand the data can partially support in terms of outcomes, but that is not the same as clinical equivalence or substitutability. A prescriber switching you between medicines would assess your history, response and current health, not just match numbers. The detail behind any dose conversion reflects that complexity.

What trial evidence shows at Mounjaro 10 mg and Wegovy 2.4 mg

The most direct evidence comparing these medicines comes from SURMOUNT-5, a head-to-head trial published in the New England Journal of Medicine in 2025, which found tirzepatide produced greater average weight reduction than semaglutide 2.4 mg over 72 weeks in adults with obesity and without diabetes. That result covers the tirzepatide programme as a whole, not specifically 10 mg, because participants were titrated to their highest tolerated dose.

Looking at dose-level data from the separate SURMOUNT-1 trial: tirzepatide 10 mg produced meaningful average weight reductions, sitting between the 7.5 mg and 15 mg results, with the 15 mg arm reaching around 20–21% average loss. Wegovy 2.4 mg in the STEP 1 trial showed approximately 15% average weight reduction over 68 weeks, as reported in the NEJM STEP 1 publication. These figures come from different trials with different populations, so they are context for a conversation with a prescriber, not a head-to-head verdict on 10 mg specifically.

The table below sets out the factual comparison across the key dimensions. Numbers are drawn from published trials and approved UK product information.

Sources: NICE technology appraisal TA1026 (tirzepatide); NICE TA875 (semaglutide); NEJM SURMOUNT-5 (2025); NEJM STEP 1 (2021).

Which medicine is more likely to suit you at this stage of treatment?

The honest answer is that the right choice depends on factors a brief comparison table cannot capture: your medical history, any medicines you already take, how you have responded to treatment so far, and your own preferences about injecting. Mounjaro 10 mg sits at a mid-point in that medicine's schedule; someone already tolerating 7.5 mg well might be titrated upward to 10 mg by their prescriber. For someone considering a switch from Wegovy, the question is different again, see the specific comparison of 2.4 mg Wegovy and 10 mg Mounjaro for that context.

A useful reference point: how the highest Mounjaro dose compares to Wegovy is a separate question, because the 15 mg results tend to be where the programme-level advantage over semaglutide is most pronounced. Conversely, Mounjaro 5 mg sits considerably earlier in the schedule and suits a different stage of treatment entirely.

Side effects across both medicines are mainly gastrointestinal (nausea, loose stools, occasional vomiting) and are most noticeable after starting or stepping up a dose. They usually ease within a week or two. The NHS medicines pages for tirzepatide and semaglutide cover these in full alongside guidance on when to seek medical help.

How a prescriber at nume reviews this choice

At nume, a real clinician reads every consultation, not an algorithm. When you describe your current treatment, your dose history and your goals, the prescriber can explain whether 10 mg Mounjaro makes clinical sense for you, or whether a different dose or medicine would be more appropriate. If you're switching from Wegovy, they'll ask for evidence of your current treatment before making any recommendation. Your treatment, once approved and dispensed from our GPhC-registered pharmacy, arrives the next working day via DPD in a plain, unbranded box, with the KwikPen inside ready to refrigerate.

If you want to understand the broader cost context before booking, a comparison of what each medicine typically costs privately may help. For a wider view of both medicines, the Wegovy vs Mounjaro overview covers everything from mechanism to eligibility in one place. Which medicine suits you is a clinical decision our prescribers make with you, start your free consultation to get that conversation going.