Mounjaro®
Starting from £179.99/mo
Start journey Learn moreHow the dose schedules, trial results and eligibility criteria stack up
The decision you're actually making
If you're researching the Mounjaro vs Wegovy dose comparison, you're probably not choosing between two brands out of idle curiosity. More likely you've been offered one, heard about the other, or you're wondering whether switching makes sense. That's a reasonable place to be. The two medicines share a once-weekly injection format and a broadly similar titration principle (start low to let your body adjust, then step up) but the numbers, the intervals and the mechanism behind them are different enough to matter.
Wegovy begins at 0.25mg and climbs through four steps (0.25mg, 0.5mg, 1.0mg, 1.7mg) before reaching the standard 2.4mg maintenance dose, typically over around 16 weeks of monthly increases. The MHRA approved an even higher 7.2mg option in January 2026, and a dedicated single-dose 7.2mg pen was approved on 14 April 2026, for adults with a BMI of 30 or above. You can read more about how those two medicines compare overall on the Wegovy vs Mounjaro overview page.
Mounjaro starts at 2.5mg, which exists specifically to help your system settle rather than to produce weight loss. From there it moves through 5mg, 7.5mg, 10mg, 12.5mg and 15mg, each step available in its own pre-filled KwikPen. The prescriber decides the pace. Six strengths means more room to find a dose that works without pushing through side effects.
Putting the numbers side by side
The table below captures the core structural differences. Any weight-loss figures come from the clinical trials cited alongside each row; they're population averages, not individual predictions.
| Feature | Wegovy (semaglutide) | Mounjaro (tirzepatide) |
|---|---|---|
| Mechanism | GLP-1 receptor agonist | Dual GIP + GLP-1 receptor agonist |
| Starting dose | 0.25mg weekly | 2.5mg weekly |
| Standard maintenance dose | 2.4mg weekly | Up to 15mg weekly (prescriber-guided) |
| Higher-dose option | 7.2mg weekly (approved Apr 2026) | 15mg is already the maximum |
| Number of dose steps | 5 steps to 2.4mg; 1 further to 7.2mg | 6 steps to 15mg |
| Average weight loss (trial) | ~15% at 2.4mg (STEP 1, 68 weeks) [STEP 1, NEJM]; ~20.7% at 7.2mg | ~20–21% at 15mg (SURMOUNT-1, 72 weeks) [SURMOUNT-1, NEJM] |
| Head-to-head evidence | SURMOUNT-5 (72 weeks, adults with obesity, no diabetes) showed tirzepatide produced greater average weight reduction than semaglutide 2.4mg [SURMOUNT-5, NEJM 2025] | |
The head-to-head gap narrows considerably at 7.2mg semaglutide. There is no published trial directly comparing 7.2mg Wegovy against Mounjaro 15mg, so those figures should be read carefully rather than treated as a settled ranking. For more detail on how individual dose levels map across the two medicines, the Wegovy mg vs Mounjaro dose breakdown covers that question thoroughly.
Does the dose difference change who can use each medicine?
Both medicines share similar licensed eligibility: adults with a BMI of 30 or above, or 27–29.9 alongside at least one weight-related condition such as high blood pressure, type 2 diabetes, high cholesterol or obstructive sleep apnoea. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. The 7.2mg Wegovy pen carries a narrower licence, restricted to adults with a BMI of 30 or above only.
Eligibility is not simply a number on the scales. A prescriber reviews your full picture before approving anything: current medicines, relevant health history, whether you've tried other weight-management approaches. The Mounjaro vs Wegovy dosage and eligibility guide explores how those clinical factors play into which schedule is appropriate. The NICE appraisal of tirzepatide is a useful reference for the clinical thresholds the NHS uses; you can read it at the NICE TA1026 recommendations page.
Practically, if someone is already established on one medicine and considering a switch, that conversation belongs with a prescriber who can review what's happened so far. A guide to what that transition involves is available on the Mounjaro to Wegovy dose conversion page.
What the dose difference means in practice
One thing people notice when looking at these two schedules is that the numbers don't translate directly. Mounjaro's 2.5mg starter dose sounds much larger than Wegovy's 0.25mg, but the medicines work differently and operate at different concentrations. There is no simple conversion formula. The Mounjaro equivalent dose to Wegovy page goes into the pharmacology behind why cross-medicine comparisons based on the milligram figure alone are misleading.
Side-effect profiles are similar across both: nausea, constipation, loose stools, indigestion and fatigue are the most commonly reported, particularly after starting or stepping up. These tend to settle within a week or two for most people, though everybody's experience is different. The NHS medicines page for tirzepatide on the NHS website sets out what to watch for and when to contact a clinician.
Cost is another practical factor. Because Mounjaro has six pen strengths and Wegovy has more, pricing varies not just between the two medicines but across their dose ranges. The price difference between Mounjaro and Wegovy gives an honest breakdown of what private treatment typically costs by dose. At nume, one price covers consultation, prescription, treatment and aftercare — no hidden extras, no subscription. Which medicine is right for you is a clinical decision, made with our prescribers based on your individual assessment. If you're ready to talk it through, start your free consultation and a GPhC-registered prescriber will review your answers the same day.
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