Medication vs Medication

Mounjaro vs Wegovy

A practical UK comparison focused on what is genuinely different — not which brand has the loudest marketing.

The direct head-to-head needs a 2026 footnote.

SURMOUNT-5 compared tirzepatide with semaglutide at 1.7/2.4 mg and found greater mean loss with tirzepatide at 72 weeks. Wegovy now also has a UK-licensed 7.2 mg injectable maintenance option in adults with obesity if needed, so the head-to-head result should not be mislabelled as tirzepatide versus 7.2 mg semaglutide.

Mounjaro

Up to ~20%+ mean loss in obesity trials; direct head-to-head 20.2% at 72 weeks vs 13.7% semaglutide 1.7/2.4 mg in SURMOUNT-5

VS

Wegovy injection

STEP 1: mean -14.9% at 68 weeks with 2.4 mg; 7.2 mg is now a licensed maintenance option for adults with obesity if needed

Side-by-side

MounjaroWegovy injection
Active ingredienttirzepatidesemaglutide
FormWeekly injectionWeekly injection
FrequencyOnce weeklyOnce weekly
LicenceUK weight management licenceUK weight management licence
NHS contextNICE-recommended; NHS access is phased / pathway-dependentNICE-recommended in specialist weight-management pathways; access depends on pathway
EvidenceVery strongVery strong
Weight-loss evidenceUp to ~20%+ mean loss in obesity trials; direct head-to-head 20.2% at 72 weeks vs 13.7% semaglutide 1.7/2.4 mg in SURMOUNT-5STEP 1: mean -14.9% at 68 weeks with 2.4 mg; 7.2 mg is now a licensed maintenance option for adults with obesity if needed
MaintenanceLong-term treatment may be needed; stopping can be followed by regainLong-term support/treatment matters; weight regain after stopping has been demonstrated
GI considerationsCommon GI effects, especially during escalationCommon GI effects; dose escalation is used to improve tolerability

Reasons to discuss Mounjaro

  • Highest head-to-head mean weight loss among the established injectable options in SURMOUNT-5
  • Weekly dosing
  • Strong appetite / food-noise effect for many users
  • Weight-management and maintenance licence

Trade-offs

  • Injection
  • GI side effects can be limiting
  • Access and NHS rollout are not the same as NICE eligibility
  • Ongoing treatment cost/maintenance matters if private

Reasons to discuss Wegovy injection

  • Large evidence base
  • Weekly dosing
  • Cardiovascular outcome evidence in appropriate populations
  • 2.4 mg established; 7.2 mg injectable option now licensed for adults with obesity if needed

Trade-offs

  • Injection
  • GI effects
  • The new 7.2 mg option should not be compared using old 2.4 mg-only trial assumptions
  • NHS access remains pathway-limited

Which is stronger for weight loss?

Mounjaro is rated 10/10 and Wegovy injection 8/10 in our comparison framework. That rating summarises the obesity evidence available for the licensed formulation; it is not a prediction of your result.

Which is easier to live with?

Mounjaro: Once weekly. Wegovy injection: Once weekly. For some people a weekly injection is easier than a daily tablet; for others avoiding a needle is decisive.

NHS vs private reality

NICE-recommended; NHS access is phased / pathway-dependent. NICE-recommended in specialist weight-management pathways; access depends on pathway. NICE criteria and NHS availability are related but not identical, so check the current pathway rather than assuming a clinically eligible medicine is immediately available through a GP.

Maintenance matters

Long-term treatment may be needed; stopping can be followed by regain. Long-term support/treatment matters; weight regain after stopping has been demonstrated. A treatment comparison that ends at the point of weight loss is incomplete.

Questions to ask a prescriber

  • Which option is actually licensed and clinically appropriate for my health history?
  • How do the expected benefits compare for someone with my diabetes/cardiovascular history?
  • What side effects should make me contact you?
  • What will monitoring involve?
  • What is the plan if I cannot tolerate the maintenance dose?
  • What happens if I stop?

Sources

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