Mounjaro vs Wegovy
Both are weekly GLP-1 injections with strong trial data. They differ in mechanism, average results, side effect patterns and price. Here is the comparison we give our own patients.
Which produces more loss? #
On headline averages, Mounjaro leads: about 21% at the highest Mounjaro dose versus about 15% for Wegovy 2.4 mg. The higher 7.2 mg Wegovy dose narrows the gap considerably (about 20.7%). In SURMOUNT-5, the direct head-to-head trial, tirzepatide produced greater average loss than semaglutide 2.4 mg over 72 weeks.
Averages are not destinies. Some individuals respond better to one molecule than the other, and tolerability often matters more than a two-point difference in the mean.
Side effect differences #
Both cause the same family of effects, nausea, constipation, diarrhoea, reflux. In trials, nausea rates were broadly similar. Tirzepatide's GIP action may soften nausea slightly for some people, though individual experience varies widely. Neither is clearly "gentler", the right answer is whichever your body tolerates, discovered slowly with your prescriber.
Practical differences #
- Contraception. Mounjaro can reduce pill absorption at dose changes. Wegovy does not. For many women this alone settles the choice.
- Price. Wegovy's starter doses cost less, so the early months are cheaper. At maintenance doses the costs converge.
- History. Wegovy's semaglutide has the longer published record, including the SELECT cardiovascular outcomes trial.
- Tablet option. Only semaglutide currently has an oral form (Wegovy tablets) if you later want to move off injections.
Can you switch between them? #
Yes, switching is common and straightforward with prescriber oversight. You typically start the new medicine at a lower dose than a direct conversion suggests, because tolerance does not transfer perfectly. The switching guide covers conversions in detail.
How we help you decide #
Your health check captures the factors which separate the two: contraception, reflux history, diabetes medicines, budget and needle preference. Your prescriber then recommends one, with reasons you can question. If the first choice does not suit you after a fair trial, switching is part of the service, not a failure.
| Mounjaro | Wegovy | |
|---|---|---|
| Active ingredient | Tirzepatide | Semaglutide |
| How the medicine works | Acts on GLP-1 and GIP receptors | Acts on GLP-1 receptors |
| Average trial loss | Up to 21% at 72 weeks (SURMOUNT-1, 15 mg) | About 15% at 68 weeks (STEP 1, 2.4 mg). Up to 20.7% at 7.2 mg (STEP UP) |
| Dose range | 2.5 mg to 15 mg, six steps | 0.25 mg to 2.4 mg, five steps. 7.2 mg as three weekly doses |
| Starting price | To be confirmed | To be confirmed |
| Contraceptive pill | Can reduce absorption, barrier method for 4 weeks after each dose change | No known interaction |
| Missed dose window | 4 days (96 hours) | 5 days |
| Safety record | Licensed 2022 (diabetes), large obesity trial programme | Longest GLP-1 obesity dataset, including cardiovascular outcomes (SELECT) |
Questions people ask
Is Mounjaro stronger than Wegovy?
On average, yes. The highest Mounjaro dose produced about 21% average loss in trials versus about 15% for Wegovy 2.4 mg. Individual responses vary, and tolerability often matters more than the headline number.
Which has worse side effects?
Neither consistently. Both cause the same family of gut effects at similar rates in trials. Your own tolerance is discovered gradually, one dose step at a time.
Can I switch from Wegovy to Mounjaro?
Yes, with prescriber oversight. You usually start Mounjaro at a lower dose than your Wegovy dose might suggest, then titrate up again.
Understand your treatment options
Aero’s treatment prices and service inclusions will be confirmed before booking opens. Ask which prescribing, dispensing, delivery and follow-up costs are included in your quote.
Page information
- Summary
- Mounjaro vs Wegovy compared: trial results, side effects, doses, the contraceptive pill interaction, price and how prescribers choose between them.
- Publisher
- Aero Clinic, operated by AERO HEALTHCARE LTD.
- Editorial update
- Clinical review
- Pending. An editorial update is not a clinical sign-off.
Cite as: Mounjaro vs Wegovy, Aero Clinic (https://www.cagri.co.uk), AERO HEALTHCARE LTD. https://www.cagri.co.uk/mounjaro-vs-wegovy. Editorial update: 4 November 2026. Clinical review pending.