Mounjaro vs Wegovy UK: Which Weight Loss Injection Is Right for You?

Both Mounjaro (tirzepatide) and Wegovy (semaglutide) are MHRA-approved weekly injections for weight management in the UK. This guide compares clinical trial outcomes, UK prices, side effects, and suitability to help you make an informed decision with your prescriber.

ExpressDiscountCode Verdict

Mounjaro generally produces greater weight loss (up to 22.5% vs 15% in clinical trials) and is often cheaper per month in the UK. Wegovy has a longer safety track record and additional cardiovascular benefits. For most new patients without contraindications, Mounjaro is currently the stronger choice — but always discuss with your prescriber.

Head-to-Head Comparison

Key facts compared side by side. Updated 27 March 2026.

Feature Mounjaro Wegovy
Active ingredientTirzepatideSemaglutide
MechanismDual GIP + GLP-1 agonistGLP-1 agonist only
Injection frequencyOnce weeklyOnce weekly
Starting dose2.5mg0.25mg
Maximum dose15mg2.4mg
Avg. weight loss (trials)Up to 22.5%Up to 15%
UK approval statusMHRA approved (2023)MHRA approved (2022)
NHS availabilityLimited (NICE 2024)Limited
Cheapest UK private price~£121/month~£150/month
Pen deviceKwikPen (auto-injector)Pen injector
ManufacturerEli LillyNovo Nordisk

* Weight loss figures from SURMOUNT-1 (tirzepatide) and STEP-1 (semaglutide) clinical trials. Individual results vary. Always consult a prescriber.

Pros & Cons

Mounjaro (Tirzepatide)

Greater average weight loss in head-to-head trials
Dual mechanism targets two appetite-regulating hormones
Often cheaper per month than Wegovy at equivalent doses
Wider range of doses allows more precise titration
NICE approved for NHS use (2024)
Newer medication — less long-term safety data than semaglutide
May cause more GI side effects in some patients
Not suitable for those with a personal/family history of MTC
Requires a valid UK prescription
Find Mounjaro Discount Codes →

Wegovy (Semaglutide)

Longer safety track record (semaglutide approved since 2021)
Also approved for cardiovascular risk reduction (SELECT trial)
Widely available across UK pharmacies
Well-tolerated by most patients
Available as Ozempic at lower doses for type 2 diabetes
Lower average weight loss than Mounjaro in clinical trials
Single GLP-1 mechanism vs Mounjaro's dual action
Often more expensive than Mounjaro at comparable doses
Supply shortages have affected availability
Find Wegovy Discount Codes →

Clinical Trial Weight Loss Data

Both medications have been tested in large-scale randomised controlled trials. The figures below represent average weight loss at the highest approved dose over approximately 68–72 weeks.

Mounjaro 15mg (SURMOUNT-1)22.5%

Average body weight reduction over 72 weeks vs placebo

Wegovy 2.4mg (STEP-1)15.0%

Average body weight reduction over 68 weeks vs placebo

Clinical trial results represent averages under controlled conditions. Individual weight loss varies based on starting weight, diet, exercise, adherence, and other factors. These figures should not be used as personal weight loss predictions. Always consult a qualified prescriber.

UK Price Comparison

Private prescription prices vary significantly between UK pharmacies. The table below shows indicative price ranges for each medication at their starting and maintenance doses. Use our full comparison tools to find the cheapest verified price.

DoseMounjaro (from)Wegovy (from)
Starting dose£121/month (2.5mg)~£150/month (0.25mg)
Mid titration£144/month (5mg)~£170/month (0.5mg)
Maintenance£260/month (10mg)~£250/month (1.7mg)
Full maintenance£260/month (15mg)~£250/month (2.4mg)

Prices are indicative and based on the cheapest verified prices on ExpressDiscountCode as of 27 March 2026. Wegovy prices are approximate as we do not currently track all Wegovy pharmacies. Always verify at checkout.

Mounjaro vs Wegovy: Frequently Asked Questions

Mounjaro and Wegovy are prescription-only medicines. This page is for informational purposes only and does not constitute medical advice. Always consult a qualified UK prescriber before starting, switching, or stopping any weight loss medication. ExpressDiscountCode is a price comparison and information service.

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